Sean Russell Poppen (born March 15, 1994) is an American professional baseball pitcher for the Tecolotes de los Dos Laredos of the Mexican League.

He has previously played in Major League Baseball (MLB) for the Minnesota Twins, Pittsburgh Pirates, Tampa Bay Rays, and Arizona Diamondbacks.

He split the 2019 minor league season between the Pensacola Blue Wahoos and the Rochester Red Wings, going a combined 7–4 with a 4.01 ERA over 89.2 innings.

[9] With the 2020 Minnesota Twins, Poppen appeared in 6 games, compiling a 0–0 record with 4.70 ERA and 10 strikeouts in 7.2 innings pitched.

[14] He finished the season appearing in 20 games for Arizona, registering a 1–1 record and 4.67 ERA with 21 strikeouts in 17.1 innings pitched.

[20] On January 29, 2025, Poppen signed with the Tecolotes de los Dos Laredos of the Mexican League.

[21] In 2016 Poppen graduated (with honors) from Harvard, double majoring in Chemistry and Physics, and Engineering Sciences.