Lamar University (Lamar or LU) is a public university in Beaumont, Texas, United States. Lamar has been a member of the Texas State University System since 1995. It was the flagship institution of the former Lamar University System. As of the fall of 2024, the university enrollment was 17,850 students. Lamar University is accredited by the Southern Association of Colleges and Schools and named for Mirabeau B. Lamar, the second president of the Republic of Texas.

The university campus has an urban setting and the core campus of LU is 299-plus acres. LU is organized into five undergraduate colleges, one graduate college and an honors college.