U.S. Route 425 (US 425) is a north–south United States highway that travels in the U.S. states of Mississippi, Louisiana, and Arkansas. It was first commissioned in 1989.

The route's northern terminus is in Pine Bluff, Arkansas, at an interchange with Interstate 530/U.S. Route 63/U.S. Route 65/U.S. Route 79/US 65B/AR 190. Until 2005, its southern terminus was in Bastrop, Louisiana, at an intersection with U.S. Route 165. In 2005, it was extended to Natchez, Mississippi, at an intersection with U.S. Route 61.

US 425 is an amalgamation of former state highways. Most of US 425 in Louisiana, for example, is merely a concurrency with Louisiana Highway 15 (LA 15).

The route number does not follow the numbering convention for U.S. Highways established by the American Association of State Highway and Transportation Officials. The number 425 would normally be used a spur of U.S. Route 25. However, the two routes have never connected.

The southern terminus of US 425 is at a signalized intersection with US 61 and US 84 in Natchez. The route travels northwest through the city concurrent with US 84 to the Natchez–Vidalia Bridge, along which the two routes cross the Mississippi River into Louisiana.

After entering Louisiana, the concurrency with US 84 continues for approximately 14 miles to Ferriday. US 425 then splits and heads northeast, running concurrently with LA 15 through mostly farmland and small towns. Just north of Clayton is the southern terminus of US 65. Passing through Winnsboro the highways split at Archibald. LA 15 continues northwest to Monroe, LA while US 425 heads north to Rayville where it crosses I-20. At Mer Rouge, it intersects US 165 and the two highways run concurrent to Bastrop, LA. A few miles north of Bastrop, US 425 crosses into Arkansas south of Crossett.

The route enters Arkansas near Rawls and runs north through rural Ashley County. Highway 425 forms a concurrency with US 82 east of Crosett, with the two routes running north through farmland and trees to Hamburg, the county seat of Ashley County. In Hamburg, the routes are joined by Highway 8, which runs east and west across the southern part of the state. North of the junction, the three routes pass the First United Methodist Church and historic properties within the Hamburg Commercial Historic District before US 82 turns east at St. Louis Street and US 425/AR 8 run north out of Hamburg. Passing more agricultural land, Highway 8 turns west in Fountain Hill just before the Drew County line.

Further north US 425 intersects Highway 133 in Lacey and Highway 172 before entering Monticello. The highway serves the University of Arkansas at Monticello in the southern part of town, also passing the Monticello Elementary School. US 425 intersects University Drive and continues north as a four–lane road. There is an interchange with Jordan Drive (AR 83S), after which US 425 enters residential Monticello. The route now curves to the west side of town, with Main Street (AR 83) serving downtown Monticello. Highway 83 was the previous alignment of AR 13, which US 425 replaced upon designation in 1989. There are plans to bypass Monticello even more efficiently as part of Interstate 69's extension into Arkansas.

US 425, now four–lane with center turn lane format, intersects US 278/Highway 35 at a busy intersection. Highway 35 forms a short concurrency north with US 425, which proceeds north and out of Monticello. After AR 35 turns west, Highway 425 has many rural junctions with county routes. Upon entering Lincoln County, the route passes the historic Mt. Zion Presbyterian Church in Relfs Bluff and the Parker House before entering Star City. Downtown, the highway forms a concurrency with Highway 11, which ends near the Lincoln County Courthouse and the Star City Commercial Historic District. The highway continues north through rural areas before intersecting US 65 in Jefferson County. US 65/US 425 run concurrent west to a high–volume interchange with I-530/US 63/US 79/US 65B/AR 190, where US 425 terminates.

In Arkansas, US 425 replaced the southern half of Arkansas Highway 13, which was an original state highway in the area. The route is essentially the same as it was at inception in the 1926 state highway plan, connecting the major cities in its area of southeast Arkansas. Highway 13 now runs in north central Arkansas. Most of US Route 425 was repaved in 2010 within Ashley County.

Louisiana Highway 137
Location	Morehouse and Richland Parishes
Length	18.08 mi (29.10 km)
Existed	1955–2005

Louisiana Highway 137 (LA 137) was a state highway in Louisiana that serves Richland Parish and Morehouse Parish. It spanned 18.08 miles (29.10 km) in a south to north direction. LA 137 is now signed as U.S. 425 for its entire length.

From the south, LA 137 began as a state highway at an intersection with LA 15 north of Mangham in the small town of Archibald. It went north and intersected LA 584 before intersecting LA 135.

Passing under I-20, LA 137 met LA 3048 in the town of Rayville. After intersecting US 80, LA 137 entered Morehouse Parish, continuing north as a two-lane road until it swapped the U.S. 425 designation with LA 133.

LA 137 is a divided, four-lane highway south of Rayville, a pair of two one-way roads inside of Rayville, and an undivided, two-lane road north of Rayville. Before the 1955 renumbering, LA 137 was State Route 47 from Archibald to Rayville. The current routing for LA 137 did not exist, and travelers had to take US 80 west, then State Route 47 (Current LA 133) to Oak Ridge.

LA 137 was removed from the state highway system in 2005, when US 425 was extended south to Mississippi. It is still signed, however, as LA 137 and US 425.

State	County	Location	mi	km	Destinations	Notes
Mississippi	Adams	Natchez	0.0	0.0	US 61 / US 84 east / Trace Town Drive – Vicksburg, Brookhaven, Woodville, Baton Rouge, Airport	south end of US 84 / US 61 Bus. overlap
			0.6	0.97	Homochitto Street (MS 928 / US 61 Bus. north) - Downtown Natchez	north end of US 61 Bus. overlap
Mississippi River			1.4 0.0	2.3 0.0	Natchez-Vidalia Bridge
Louisiana	Concordia	Vidalia	0.1	0.16	LA 131
		Taconey	2.515	4.048	LA 3180 (J. Logan Sewell Drive)
		​	5.637	9.072	LA 3196
		​	8.442	13.586	LA 3232
		Ferriday	10.225	16.456	US 84 west / LA 15 south / LA 568 – Jonesville	north end of US 84 overlap; south end of LA 15 overlap
			10.575	17.019	LA 903 – Lake Concordia, Lake St. John
		Clayton	16.313	26.253	US 65 north – Newellton, Tallulah, Lake Providence, Lake Bruin State Park
			16.841	27.103	LA 566
	Tensas River		17.0	27.4	Tensas River Lift Bridge
	Catahoula	Lee Bayou	20.106	32.357	LA 567
		Foules	24.824	39.950	LA 921
		Sicily Island	29.078	46.797	LA 8
		Peck	34.407	55.373	LA 913
		​	36.129	58.144	LA 3148
	Franklin	Wisner	38.453	61.884	LA 562	south end of LA 562 overlap
			38.75	62.36	LA 562	north end of LA 562 overlap
		​	39.725	63.931	LA 875
		Gilbert	43.083	69.335	LA 128	south end of LA 128 overlap
			43.237	69.583	LA 572
			43.658	70.261	LA 128	north end of LA 128 overlap
		​	46.704	75.163	LA 3210
		​	46.823	75.354	LA 1242
		​	48.489	78.035	LA 3210
		Winnsboro	51.063	82.178	LA 3201
			51.397	82.715	LA 864
			52.090	83.831	LA 865
			52.621	84.685	LA 4	south end of LA 4 overlap
			52.945	85.207	LA 4 / LA 17 / LA 130	north end of LA 4 overlap
			55.523	89.356	LA 868
		​	57.765	92.964	LA 867
		Baskin	58.554	94.234	LA 577
			59.397	95.590	LA 857
	Richland	Mangham	63.453	102.118	LA 132	south end of LA 132 overlap
		​	64.177	103.283	LA 132	north end of LA 132 overlap
		Archibald	66.215	106.563	LA 856
		​	66.521	107.055	LA 15 north	north end of LA 15 overlap
		​	70.2	113.0	LA 584	south end of LA 584 overlap
		​	70.321	113.171	LA 584	north end of LA 584 overlap
		Rayville	73.253	117.889	LA 135 – Alto
			73.768	118.718	I-20 – Monroe, Vicksburg	I-20 exit 138
			74.671	120.171	LA 3048 east
			75.203	121.027	US 80
	Morehouse	​	84.486	135.967	LA 133 south – Girard	south end of LA 133 overlap
		Oak Ridge	85.179	137.082	LA 134 – Collinston, Monroe	south end of LA 134 overlap
			85.832	138.133	LA 134 – Epps	north end of LA 134 overlap
		​	94.023	151.315	LA 3051 – Horseshoe Lake
		Mer Rouge	96.676	155.585	LA 2 east – Oak Grove	north end of LA 133 overlap; south end of LA 2 overlap
			96.705	155.632	US 165 north / LA 138 – Collinston, Bonita	south end of US 165 overlap
		Bastrop	101.42	163.22	LA 830-3 (Peach Orchard Road)
			101.906	164.002	LA 3051
			103.184	166.059	LA 830-4 (Cooperlake Road)
			103.536	166.625	LA 830-6 (McCreight Street)
			103.639	166.791	LA 830-5 (Elm Street)
			104.313	167.876	US 165 south / LA 2 west (West Madison) / LA 139 south / LA 593 south (South Washington)	north end of US 165 / LA 2 overlap; south end of LA 593 overlap
			104.677	168.461	LA 830-1 (Harrington Avenue)
			105.134	169.197	LA 593 north (Bonner Ferry Road) – Bussey Brake Reservoir	north end of LA 593 overlap
			105.666	170.053	LA 830-3 (Cherry Ridge Road)
		​	105.742	170.175	LA 830-2 (Shelton Road)
		​	106.123	170.788	LA 830-6 (McCreight Street)
		Log Cabin	108.784	175.071	LA 140
		​	111.799	179.923	LA 593 – Bussey Brake Reservoir
		​	113.977	183.428	LA 142 – Crossett, AR
		​	114.214	183.810	LA 1257 – Chemin-A-Haut State Park
		​	117.213	188.636	LA 590
Louisiana-Arkansas border			120.969 0.0	194.681 0.0
Arkansas	Ashley	​	9.4	15.1	US 82 west / AR 52 east – Crossett, El Dorado	south end of US 82 overlap
		​	12.0	19.3	AR 52 west – North Crossett, UAM College of Technology-Crossett
		Hamburg	15.7	25.3	AR 189 west (West Jackson Street)
			16.0	25.7	AR 8 east (East Parker Street) – Parkdale, Overflow NWR	south end of AR 8 overlap
			16.2	26.1	AR 189 north (West Washington Street) to AR 133
			16.3	26.2	US 82 east – Lake Village	north end of US 82 overlap
		Fountain Hill	25.5	41.0	AR 8 west to AR 133 south – Johnsville, Crossett	north end of AR 8 overlap
			26.0	41.8	AR 160 west
	Drew	Lacey	32.8	52.8	AR 133 south to AR 160
		White Hall	40.5	65.2	AR 172 west
		​			US 278 Byp. east	Western terminus of US 278 Byp.; future I-69
		Monticello	42.7	68.7	AR 83 south (University Drive) – University of Arkansas Monticello
			42.8	68.9	AR 83 north
			44.2	71.1	AR 83S	interchange
			45.4	73.1	US 278 – Warren, McGehee
		​	46.7	75.2	AR 35 north – Lake Monticello
	Lincoln	​	65.1	104.8	AR 54 east – Little Garnett
		Star City	66.7	107.3	AR 293 south (Cane Creek Road) – Cane Creek State Park
			67.2	108.1	AR 11 south (West Franklin Street)
			67.8	109.1	AR 11 north (Arkansas Street) / AR 114 west (Arkansas Avenue)
		​	77.8	125.2	AR 199 north / Allegiance Road – Tarry, Moscow
	Jefferson	​	88.5	142.4	US 65 south / AR 81 north – Grady, Lake Village	south end of US 65 overlap
		Pine Bluff	90.5	145.6	AR 980 south – Airport
			91.0	146.5	US 63 north / US 79 north / US 65B north / AR 190 west (Harding Avenue) – Downtown Pine Bluff	Signed as exit 46; signed for Harding Avenue southbound, Downtown northbound
					I-530 north (US 63 south / US 65 north / US 79 south) – Little Rock	Continuation north; north end of US 65 overlap
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus

• Endpoints of U.S. Highway 425

Browse numbered routes
← MS 424	MS	→ MS 427
← LA 136	LA (LA 137)	→ LA 138
← LA 424	LA (US 425)	→ LA 427
← US 412	AR	→ I-430