In the U.S. state of Texas, U.S. Highway 377 is a U.S. Highway that begins at US 90 in Del Rio and heads north through Fort Worth and into Oklahoma.

When US 377 was commissioned in 1930, US 77 connected Dallas, Texas with the north and south, but nearby Fort Worth lacked a direct northern connection. US 377 connected US 77 in Denton, Texas with US 81 in Fort Worth, Texas, creating a parallel route between Denton and Hillsboro, Texas, where US 81 met US 77. When the Interstate highway system was built, Interstate 35 paralleled the Dallas/Fort Worth split with routes I-35E through Dallas (along US 77) and I-35W through Fort Worth (along US 377 and US 81).

The southern terminus is in Del Rio, Texas at an intersection with U.S. Highway 90. It goes north of town co-signed with U.S. Highway 277 for 20 miles (32 km). After splitting off, it enters Edwards County and Carta Valley. It meets SH 55 at the county seat, Rocksprings, before serving as the western terminus of SH 41. It heads northeast into Kimble County, crossing the county line near Telegraph. At Junction, Texas, it meets both Interstate 10 and US 83. It then continues northeast through London, extreme southeastern Menard County, and Mason County. In Mason County, US 377 passes through Streeter before forming a concurrency with SH 29 near Grit. In Mason, SH 29 splits off to its own alignment while US 377 turns north to join U.S. Highway 87.

US 87/377 head north together into Brady, where they meet US 190, the southern terminus of US 283, and SH 71. US 377 splits off to the north and heads to Mercury and crosses the Colorado River near Winchell. In Brownwood, US 377 joins with U.S. Highway 67, following its routing all the way to Stephenville, where US 377 splits off on its own again. US 377 then enters Hood County, where it passes through the county seat, Granbury. It cuts the corners of both Johnson County and Parker County before entering Tarrant County and the Dallas-Fort Worth Metroplex.

US 377 crosses Interstate 20 at exit 429A in Benbrook. It then enters Fort Worth proper, meeting SH 183 and Spur 580. It runs northeast on Camp Bowie Blvd. to Interstate 30, with which it begins a concurrency. At the Interstate 35W junction, it heads north along that highway before splitting off at Exit 52A (Belknap St.). It heads due north at the Denton Highway and continues to run parallel to I-35W through many D/FW suburbs, including Haltom City, Watauga, Keller, Westlake, Roanoke, and Argyle. In Denton, it crosses Interstate 35E and has a brief concurrency with US 380 through the eastern portion of Denton.

After splitting from US 380, US 377 runs east of Aubrey, through Pilot Point, Tioga, and Collinsville, before having an interchange with US 82 at Whitesboro. It then heads north to cross Lake Texoma (the Red River) into Oklahoma.