U.S. Route 231 (US 231) in Alabama runs north–south up through the eastern half of Alabama for 306.273 miles (492.899 km). US 231 enters the state from Florida south of Madrid and exits into Tennessee, running councurrently with US 431 north of Hazel Green. US 231 passes through the major cities of Dothan, Troy, Montgomery, and Huntsville.

From the Florida state line to Wetumpka, US 231 is a major four-lane divided thoroughfare that connects Central Alabama to the Florida Gulf Coast and Panama City. Between Wetumpka and Arab, excluding its overlap with US 280 between Sylacauga and Harpersville as well as portions through major towns, the road is largely rural and two lanes. Between Arab and the Tennessee state line, the route returns to a four-lane divided highway; the route is upgraded to a limited-access freeway and adjoining frontage roads named Memorial Parkway within the city of Huntsville.

During its route through the state, US 231 runs concurrently with three state highways. Between the Florida state line and southern Dothan as well as between Huntsville and the Alabama state line, US 231 runs concurrent with unsigned State Route 1 (SR 1). Between northern Dothan and Huntsville, the route is overlaid with SR 53, which is unsigned along its portion with US 231 but does have a signed segment north of Huntsville. Finally, while bypassing Dothan, US 231 is overlaid with the signed SR 210).

In Alabama, US 231 is paired with unsigned State Route 53 (SR 53) from Huntsville to Dothan.

The route passes through mostly straight terrain between the Tennessee state line and Meridianville, which is home to its junction with Bob Wade Lane, which eventually becomes SR 255.

The route descends down a slight hill and enters Huntsville. It becomes a freeway (Memorial Parkway). It junctions with US 72 east/ Sparkman Drive. After a short concurrency with US 72, it splits off onto University Drive. The route almost immediately junctions with Interstate 565 (I-565). It then junctions with a two-part interchange (Clinton Avenue/US 431 South/SR 53 North; Governors' Drive). Here, it gains SR 53 and loses US 431. The route continues south as a freeway until it reaches a specific point when it becomes a four-lane divided highway. It passes by Redstone Arsenal Gate 3's access road, Hobbs Road. The route continues south until it reaches the Clement C. Clay Bridge. It promptly crosses the Tennessee River into Morgan County.

The route eventually junctions with SR 36. It climbs up Brindlee Mountain into Union Hill. While climbing, the route makes a slight curve from the southwest to the southeast that is easily noticeable on road maps. It then passes through Morgan City and enters Marshall County. The route heads through mountainous terrain to Arab, which is home to its junction with SR 69. This junction is a diamond interchange and is directly above the line with Cullman County.

There are no major junctions in Cullman County.

It eventually crosses the line into Blount County. The road turns to the southwest and junctions with SR 67. It quickly junctions with US 278. Eventually, the route reaches Blountsville, and past Blountsville, the route junctions with SR 79 North. It reaches Cleveland and splits off from SR 79, which continues on its right of way to Birmingham. US 231 then junctions with SR 160 West, which continues on its next right-of-way. It passes through mountains until it reaches Oneonta, which is home to its junction with SR 75. The route climbs up a high hill and descends it, now crossing into St. Clair County.

The route eventually junctions with US 11 and then I-59. It enters Ashville. It junctions with SR 23 and US 411/SR 25 North. After a moderate concurrency with the two routes, US 411 and SR 25 turn southwest towards Leeds. US 231 heads directly south towards Pell City. The route heads through extremely hilly terrain as a two-lane and three-lane road. It reaches Coal City and junctions with SR 144. It continues down through the same terrain to I-20. It reaches US 78 and then SR 34.

US 231 reaches Shelby County. It parallels the Coosa River as it reaches Vincent, which is home to its next junction with SR 25. They continue south to Harpersville. SR 25 junctions with US 231 for the last time here as US 231 turns onto US 280.

The routes then cross into Talladega County. After a long journey to Sylacauga, the route turns off of US 280 at its junction with SR 21, which is a Diamond Interchange. The route enters Coosa County near this point.

In Coosa County, the route junctions with SR 22 in Rockford. It then enters Elmore County after a long journey south.

In Elmore County, there are no major junctions until it reaches SR 9. This point is the line with the city of Wetumpka. The route junctions with SR 14 and SR 170 north of the city. Within the city, the routes (SR 9, US 231, and SR 21) junction with SR 111. The routes then enter Montgomery County.

The routes junction with SR 152/Northern Boulevard, a half-beltway around Montgomery. The routes join the half-beltway. SR 152 ends at this point, though. The routes turn from east to south and junction with Atlanta Highway. The routes junction with I-85 and gain US 80. The routes turn to the west. US 231 and US 82 turn to the south. SR 21, US 80, and SR 9 continue onward with US 82 west to I-65, US 331, and US 31. US 82 and US 231 continue onward to Pike Road, which is not a road, but a town. South of here, US 82 turns off of US 231 and US 231 continues onward on a four-lane divided highway into Pike County.

There are no major junctions in Pike County until US 231 reaches Troy. Here, the route junctions with US 29, SR 10 west, and SR 87. US 231 continues southeast to Brundidge, which is home to its junctions with SR 10 east, SR 93, and SR 125. The route then cuts a corner of Coffee County.

There are no major junctions in Coffee County.

The route then enters into Dale County. The route junctions with SR 123 and SR 51 in the far-vicinity of Ariton, Alabama. The route reaches Ozark, which is home to its junctions with SR 27, SR 249, and once again SR 123. In Midland City, the route junctions with SR 134 and SR 605. The route has officially entered the Dothan Metropolitan Area.

In Houston County, the route has no major junctions until it reaches the Ross Clark Circle, which is US 84 and SR 210. This same junction is the junction with US 231 Bus. and the point where SR 53 ultimately leaves its state-wide concurrency with US 231. The route turns south onto the Ross Clark Circle and heads to the junction with US 84 Bus. East/US 84 West. Here, US 84 leaves the Ross Clark Circle. It then continues southeast until it reaches SR 52. SR 52 does not have a business route, unlike US 231 and US 84. The route turns to the full east and junctions with US 431 once again, for the first time since Huntsville, Alabama, alongside US 431 Bus. This junction marks the southern terminus of US 431. The route turns south off of the Ross Clark Circle with SR 1. It then heads south for the Florida state line. The route junctions with SR 109 in Hodgesville and SR 605 once again in Madrid, before finally crossing the state line into Campbellton, Florida.

When US 231 was first assigned along with the rest of the United States Numbered Highway System in 1926, the route ran only as far north as Montgomery. In 1952, the route was extended through the rest of the state and on to Indiana.

The section of US 231 in Huntsville was built as a bypass around the downtown area. The original route ran up what is now Whitesburg Drive on the south side of the city, and Meridian Street in the north.

A portion on the north side of Brindlee Mountain, south of Huntsville, was damaged by a landslide in 2020. It was replaced by an elevated section.

County	Location	mi	km	Destinations	Notes
Houston	​	0.000	0.000	US 231 south – Panama City	Continuation into Florida
	​	0.324	0.521	SR 605 north – Rehobeth, Taylor	Southern terminus of SR 605
	​	7.520	12.102	Graceville (SR 109 south) / Eddins Road	Northern terminus of SR 109
	Dothan	13.264 0.000	21.346 0.000	US 231 Bus. north (SR 1 north / South Oates Street) / US 431 north / SR 210 (SR 52 Truck / Ross Clark Circle) to US 84 east – Ashford, Headland	North end of SR 1 overlap; south end of SR 52 Truck / SR 210 overlap; southern terminus of US 231 Bus. / US 431; mileposts switch from SR 1 to SR 210
		1.793	2.886	SR 52 (Hartford Highway) – Slocomb	North end of SR 52 Truck overlap; western terminus of SR 52 Truck
		3.370	5.423	US 84 west / US 84 Bus. east (SR 12 / West Main Street) – Enterprise	South end of US 84 overlap; western terminus of US 84 Bus.
		4.904 24.007	7.892 38.636	US 231 Bus. south (SR 53 south / Montgomery Highway) / US 84 / SR 210 east (Ross Clark Circle) to US 431 north – Eufaula	North end of US 84 / SR 210 overlap; south end of SR 53 overlap; northern terminus of US 231 Bus.; mileposts switch from SR 210 to SR 53
Dale	Midland City	29.857	48.050	CR 59 / SR 605 south	Northern terminus of SR 605; SR 605 is unsigned
		30.594	49.236	SR 134 – Midland City, Pinckard, Newton	Interchange
	Ozark	41.092	66.131	SR 123 south / CR 29 – Newton	South end of SR 123 overlap
		41.775	67.230	SR 123 north (South Union Avenue) / Lakeview Road – Downtown Ozark, Ariton	North end of SR 123; Downtown Ozark signed northbound only, Artion southbound only
		43.754	70.415	SR 27 north / SR 249 (Andrews Avenue) – Downtown Ozark, Fort Novosel	South end of SR 27 overlap
		44.700	71.938	SR 27 south – Enterprise	North end of SR 27 overlap
	​	53.911	86.761	SR 51 – Ariton, Enterprise
	​	56.010	90.139	SR 123 south – Ariton	Northern terminus of SR 123
Coffee	No major junctions
Pike	​	62.939	101.291	SR 125 south – Elba	Northern terminus of SR 125
	Brundidge	64.586	103.941	SR 93 north (East Main Street) – Brundidge	Southern terminus of SR 93
		65.830 179.592	105.943 289.025	SR 10 east / CR 3316 (S.A. Graham Boulevard) – Brundidge, Clio, Camden, Butler	South end of SR 10 overlap. Mileposts switch from SR 53 to SR 10.
	Troy	170.347	274.147	SR 87 south (Elba Highway) / SR 167 / South Brundidge Street – Elba, Enterprise	Northern terminus of SR 87 / SR 167
		168.272 77.150	270.808 124.161	US 29 / SR 10 west (SR 15) – Luverne, Union Springs	Interchange. Mileposts switch from SR 10 to SR 53.
Montgomery	​	89.421	143.909	SR 94 west	Eastern terminus of SR 94
	​	105.875 171.098	170.389 275.356	US 82 east (SR 6 east) – Union Springs, Eufaula	South end of US 82 / SR 6 overlap; mileposts switch from SR 53 to SR 6.
	Montgomery	162.008	260.727	SR 271 north (Taylor Road) to I-85	Southern terminus of SR 271
		158.668 136.185	255.351 219.169	US 80 west / US 82 west to I-65 (SR 6 west / SR 8 west / SR 9 south / SR 21 south / South Boulevard) / McGehee Road	North end of US 82 / SR 6 overlap; south end of US 80 / SR 8 / SR 9 / SR 21 overlap; mileposts switch from SR 6 to SR 8.
		139.293 107.478	224.170 172.969	I-85 / US 80 east (SR 8 east) to I-65 – Montgomery, Atlanta	North end of US 80 / SR 8 overlap; I-85 exit 6; mileposts switch from SR 8 to SR 9
				Atlanta Highway	Interchange via frontage roads; former alignment of US 80
		111.939	180.148	SR 152 west (Northern Boulevard) to I-65 – Birmingham, Mobile	Interchange; Eastern terminus of SR 152
Montgomery–Elmore county line	​	114.857	184.844	Colonel William R. Lawley Memorial Bridge over Tallapoosa River
Elmore	Wetumpka			South Main Street (SR 111 Truck south)	South end of SR 111 Truck overlap
		122.395	196.976	SR 170 east – Tallassee	Western terminus of SR 170; Tallassee signed northbound only
		122.736	197.524	SR 14 / SR 111 Truck north (Tallassee Highway / Coosa River Parkway) – Tallassee, Prattville	North end of SR 111 Truck overlap
		123.483 164.428	198.727 264.621	SR 9 north (Central Plank Road) – Santuck, Central	North end of SR 9 overlap; southern terminus of signed portion of SR 9; mileposts switch from SR 9 to SR 21
Coosa	Rockford	188.890	303.989	SR 22
Talladega	Sylacauga	207.585 43.979	334.076 70.777	US 280 east / SR 21 north (SR 38 east)	North end of SR 21 overlap; south end of US 280 / SR 38 overlap; mileposts switch to SR 38
	Childersburg	32.778	52.751	SR 76 east (First Street SW) / CR 008 west (Childersburg-Fayetteville Highway)	South end of SR 76 overlap
		32.192	51.808	SR 235 north (Coosa Pines Road) / River Run Road	Southern terminus of SR 235
Talladega–Shelby county line		31.782	51.148	John A. Teague Bridge over Coosa River
Shelby	​	31.106	50.060	SR 76 west (Klein Road) – Montevallo, Columbiana	North end of SR 76 overlap
	Harpersville	26.100 147.183	42.004 236.868	US 280 west (SR 38 west) / SR 25 south – Birmingham, Wilsonville	North end of US 280 / SR 38 overlap; south end of SR 25 overlap; mileposts switch from SR 38 to SR 25
	Vincent	150.904 202.174	242.856 325.368	SR 25 north – Leeds	North end of SR 25 overlap; mileposts switch from SR 25 to SR 53
St. Clair	Pell City	217.028	349.273	SR 34 east (Mays Drive) / 19th Street South	Western terminus of SR 34
		219.073	352.564	To US 78 (SR 4 / Cogswell Avenue)	Interchange
		220.360	354.635	I-20 – Atlanta, Birmingham	I-20 exit 158
	​	221.533	356.523	SR 174 west – Odenville	Eastern terminus of SR 174
	​	223.783	360.144	SR 144 east – Ragland, H. Neely Henry Dam	Western terminus of SR 144
	Ashville	233.103 192.786	375.143 310.259	US 411 south (SR 25 south) / CR 33 north	South end of US 411 / SR 25 overlap; mileposts switch from SR 53 to SR 25
		196.884	316.854	SR 23 south (Sixth Avenue)	Northern terminus of SR 23
		196.908 237.225	316.893 381.777	US 411 north (SR 25 north / Sixth Avenue) / SR 23	North end of US 411 / SR 25 overlap; mileposts switch from SR 25 to SR 53
		239.907	386.093	I-59 – Gadsden, Birmingham	I-59 exit 166
		241.036	387.910	US 11 (SR 7) – Attalla, Birmingham
Blount	Oneonta	253.964	408.715	SR 75 north (Second Avenue East) to SR 132	South end of SR 75 overlap
		253.999	408.772	SR 75 south (Second Avenue East) / Fifth Street North	North end of SR 75 overlap
	Cleveland	261.605	421.012	SR 160 west / CR 1 south – Hayden, Warrior	Eastern terminus of SR 160
		262.639	422.676	SR 79 south – Birmingham	South end of SR 79 overlap
	​	264.457	425.602	SR 79 north – Guntersville	North end of SR 79 overlap
	​	275.547	443.450	US 278 (SR 74) – Gadsden, Cullman, Holly Pond
	​	276.305	444.670	SR 67 north – Decatur	Southern terminus of SR 67
Cullman	No major junctions
Marshall	Arab	286.206	460.604	SR 69 – Guntersville, Arab, Cullman	Interchange; Arab signed northbound only, Cullman southbound only
Morgan	Lacey's Spring	303.348	488.191	SR 36 west – Hartselle	Eastern terminus of SR 36
Morgan–Madison county line	Huntsville	306.534	493.319	Clement C. Clay Bridge over Tennessee River
Madison				Begin freeway south of Weatherly Road
				Weatherly Road / Whitesburg Drive	Northbound exit and southbound entrance
				Meadowbrook Drive west	Southbound exit and northbound entrance
				Lily Flagg Road / Logan Drive / Byrd Spring Road	Northbound exit and southbound entrance
				Charlotte Drive / Logan Drive / Lily Flagg Road	Southbound exit and northbound entrance
				Martin Road / Golf Road
				Airport Road / Jones Valley Road	Jones Valley Road signed northbound only
				Drake Avenue	Northbound exit and southbound entrance
				Drake Avenue
				Bob Wallace Avenue
		316.864 333.702	509.943 537.041	US 431 south (SR 1 south / Governors Drive) / SR 53 north	North end of SR 53 overlap; south end of US 431 / SR 1 overlap; mileposts switch from SR 53 to SR 1
				Clinton Avenue — Downtown
		334.700	538.647	I-565 (US 72 Alt.)	I-565 exit 19A-B
		335.207	539.463	To US 72 west (SR 2 west / University Drive) / University Drive
				Cook Avenue / Oakwood Avenue	Northbound exit and southbound entrance
				US 72 west (SR 2 west / University Drive) / University Drive	Southbound exit and northbound entrance; South end of US 72 / SR 2 overlap
				US 72 east (SR 2 east / Sparkman Drive) / Max Luther Drive / Sparkman Drive	Northbound exit and southbound entrance; north end of US 72 / SR 2 overlap
				Oakwood Avenue	Southbound exit and northbound entrance
				East Service Road	Northbound exit and southbound entrance
				To US 72 east / Max Luther Drive / Sparkman Drive	Southbound exit and northbound entrance
				End freeway south of Mastin Lake Road
		352.958	568.031	US 231 north / US 431 north (SR 10 north)	Continuation into Tennessee
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus

• List of U.S. Highways in Alabama

Media related to U.S. Route 231 in Alabama at Wikimedia Commons

U.S. Route 231
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