Trevor John Cahill (born March 1, 1988) is an American professional baseball pitcher who is currently a free agent.

He has played in Major League Baseball (MLB) for the Oakland Athletics, Arizona Diamondbacks, Atlanta Braves, Chicago Cubs, San Diego Padres, Kansas City Royals, Los Angeles Angels, San Francisco Giants, and Pittsburgh Pirates.

Cahill was an All-Star in 2010, finishing 9th in that year's AL Cy Young Award voting, and won a World Series title with the 2016 Cubs as well as a bronze medal at the 2008 Beijing Olympics.

With the RockHounds, Cahill was 6–1 with a 2.19 ERA before shutting it down in order to compete with the United States national baseball team at the 2008 Summer Olympics in Beijing.

[5] Entering the 2009 season, Cahill was ranked 11th among Baseball America's Top 100 Prospects,[6] and made the Athletics starting rotation out of Spring training along with his Olympic teammate Brett Anderson.

He put up borderline Cy Young Award-worthy statistics, finishing the season with an 18–8 record and an ERA of 2.97, making it into the Top 5 of lowest ERA in the American League, behind Félix Hernández, Clay Buchholz, and David Price, all three considered among best pitchers in the American League.

On December 9, 2011, Cahill and Craig Breslow were traded to the Arizona Diamondbacks for Ryan Cook, Jarrod Parker, and Collin Cowgill.

Cahill finished his rocky 2014 season with a career-worst 3–12 record and a career-high 5.61 ERA in 32 games (17 starts) for the Diamondbacks.

[18] On July 2, 2015, Cahill signed a minor league contract with the Los Angeles Dodgers.

[19] He started seven games in the Dodgers farm system between three levels, going 1–3 with a 5.24 ERA, before exercising his opt out and becoming a free agent on August 14.

[22] He pitched three times in the National League Championship Series, taking the loss in Game 3.

The Cubs finished the season with a 103–58 record for an NL Central pennant and would eventually win the 2016 World Series.

Cahill did not make any postseason appearances but still won a World Series ring for the first time in his career.

On July 24, 2017, Cahill was traded with Brandon Maurer and Ryan Buchter to the Kansas City Royals for Travis Wood, Matt Strahm, and Esteury Ruiz.

[27] For the season, between San Diego and Kansas City, Cahill was 4–3 with a 3.93 ERA and led the major leagues in wild pitches, with 16.

[32] The deal proved to be disastrous as Cahill pitched to a career-worst 5.98 ERA while being demoted to the bullpen after inconsistency and trouble with the home run ball, as he allowed 25 in just 102+1⁄3 innings.

[36][37][38] Cahill attended Vista High School and committed to Dartmouth College before signing with the A's.