Route 273 is a highway in northwestern Missouri. Its northern terminus is at the Kansas state line halfway across the Missouri River near Atchison, Kansas. At this point it is concurrent with U.S. Route 59. The southern terminus is at I-29/US 71 near Tracy. All but the southeasternmost six miles (10 km) overlap Route 45. The road runs through Platte and Buchanan Counties.

County	Location	mi	km	Destinations	Notes
Platte	Fair Township	0.000	0.000	I-29 / US 71 – St. Joseph, Kansas City Route 371 begins	Southern end of Route 371 overlap; exit 20
		0.231	0.372	Route 371 north – Tracy	Northern end of Route 371 overlap
	Tracy	0.732	1.178	To Route 92 (Route 92 Spur)
	Weston Township	4.679	7.530	Route 45 south / Route JJ west – Beverly, Weston, Weston Bend State Park	Southern end of Route 45 overlap
	Weston	6.782	10.915	Route P north
		7.414	11.932	Route H north
Buchanan	Rush Township	19.046	30.652	Route 138 west – Lewis and Clark Village, Lewis and Clark State Park
		20.096	32.341	US 59 north – St. Joseph Route 45 ends	Southern end of US 59 overlap; northern end of Route 45 overlap
Missouri River		23.455– 23.728	37.747– 38.187	Amelia Earhart Memorial Bridge; Missouri–Kansas state line; Route 273 ends
				US-59 south – Atchison	Continuation into Kansas
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus