State Highway 19, also known as SH-19 or OK-19, is a 172 mile (278.6 km) long highway running through the southern part of the U.S. state of Oklahoma. It is signed east-west. SH-19 is Oklahoma's 13th longest state highway.
SH-19 begins at an intersection with US-283 in Blair, Oklahoma. SH-19 heads east from Blair for 23 miles (37 km) without intersecting another highway before meeting U.S. Highway 183 north of Roosevelt. It continues eastward, sharing a 3 mile (4.8 km) section of road with State Highway 54 before splitting off to the east and briefly overlapping with SH-115 and State Highway 58.
The next town Highway 19 encounters is Apache, north of Lake Ellsworth, where it crosses U.S. Highway 62/281. Nine miles (14½ km) later, it overlaps with U.S. Highway 277 at Cyril. These two overlap with US-81 near Ninnekah, but SH-19 splits off to the east once again within 3 miles (4.8 km).
After splitting off, SH-19 travels in a southeast direction to have a brief concurrency with State Highway 76 through Lindsay. 10 miles (16 km) later it intersects with State Highway 74 at a four-way stop in Maysville. Still continuing southeast, 10 miles (16 km) later it has an interchange with Interstate 35 and an intersection with U.S. Highway 77 in Pauls Valley.