U.S. House seat for Texas's 21st congressional district. Representatives serve two-year terms.

20 candidates filed, 2 active for the 2026 House election in Texas District 21. Party primary on Mar 3, 2026. General election on Nov 3, 2026.
| Year | Winner | Result | Runner-Up | Total Votes |
|---|---|---|---|---|
| 2024 | Chip Roy R | 61.9% | 426,423 | |
| 2022 | Chip Roy R | 62.8% | 330,081 | |
| 2020 | Chip Roy R | 52.0% | 453,750 | |
| 2018 | Chip Roy R | 50.2% | 353,617 | |
| 2016 | Lamar Smith R | 57.0% | 356,031 | |
| 2014 | Lamar Smith R | 71.8% | 188,996 | |
| 2012 | Lamar Smith R | 60.5% | 308,865 | |
| 2010 | Lamar Smith R | 68.9% | 236,545 | |
| 2008 | Lamar Smith R | 80.0% | 304,350 | |
| 2004 | Lamar S Smith R | 95.4% | 219,990 | |
| 2002 | Lamar S Smith R | 72.9% | 222,093 | |
| 2000 | Lamar S Smith R | 75.9% | 330,878 | |
| 1998 | Lamar S Smith R | 91.4% | 180,608 | |
| 1996 | Lamar S Smith R | 76.4% | 269,307 | |
| 1994 | Lamar S Smith R | 90.0% | 184,075 |