Texas's 13th congressional district is a congressional district in the U.S. state of Texas that includes most of the Texas Panhandle, parts of Texoma and northwestern parts of North Texas. The principal cities in the district are Amarillo, Gainesville and Wichita Falls.^[4] It winds across the Panhandle into the South Plains, then runs east across the Red River Valley. Covering over 40,000 square miles (100,000 km²), it is the 19th-largest district by area in the nation, the 14th-largest that does not cover an entire state, as well as the second-largest in Texas behind the 23rd congressional district. It covers more land mass than thirteen entire states. After the 2020 census was completed, the 13th district was heavily redrawn to incorporate Denton, an increasingly Democratic-leaning suburb of the Dallas-Fort Worth metroplex which had previously anchored the 26th district.^[5] With a Cook Partisan Voting Index rating of R+26, it is one of the most Republican districts in Texas.^[3]

The district has been represented in the United States House of Representatives by Republican Ronny Jackson since 2021, and previously by Republican Mac Thornberry, from 1995 until his decision not to run for reelection in 2020.^[6] As late as 1976, Jimmy Carter won 33 of the 44 counties in the district, getting 60% to 70% of the vote in many of them. While voters in the Panhandle began splitting their tickets as early as the 1940s, Democrats continued to hold most local offices, as well as most of the area's seats in the state legislature, well into the 1990s.

Since Thornberry's ouster of three-term Democrat Bill Sarpalius in 1994, however, a Democrat has only crossed the 30 percent mark in 1996, 1998 and 2000. Republicans now dominate at nearly every level of government, and there are almost no elected Democrats left above the county level. In 2012, it gave Barack Obama his lowest percentage of the vote in a congressional district. He received 18.5% of the vote. In 2016, it was Hillary Clinton's second largest margin of defeat in a congressional district after Alabama's 4th. She received an even lower percentage than President Obama four years prior, gathering 16.9% of the vote compared to Donald Trump's 79.9%.

Often in recent years, the incumbent has either run unopposed or has only a third/fourth party candidate who is opposing them. Generally, the incumbent gets over 70% of the vote, even during years with huge opposition party pickups.

• List of United States congressional districts