Jhoulys Jose Chacín Molina (Jo-LEASE Sha-SEEN;[1] born January 7, 1988) is a Venezuelan-American professional baseball pitcher who is a free agent.

He has previously played in Major League Baseball (MLB) for the Colorado Rockies, Arizona Diamondbacks, Los Angeles Angels, San Diego Padres, Milwaukee Brewers, Boston Red Sox and Atlanta Braves.

Chacín signed with the Colorado Rockies as an international free agent in 2004,[2] and was considered to be one of their top prospects prior to 2009 and 2010.

In 2010, in his first full season in MLB with the Rockies, Chacín had 9 wins, a 3.28 ERA, and led all NL rookies in strikeouts with 138.

On November 6, Chacín was removed from the 40–man roster and sent outright to the Triple–A Reno Aces; he subsequently rejected the assignment in favor of free agency.

Chacín got the start for 2019 opening day, March 28, against the St. Louis Cardinals, and got the win while also hitting a home run off of Miles Mikolas.

Chacín was placed on the disabled list on July 25, with a right oblique strain,[21] expected to sideline him for two to four weeks.

[24] He made his Red Sox debut on September 6, pitching two innings against the New York Yankees, retiring all six batters he faced including four by strikeout.

[26] On February 1, 2020, Chacín signed a minor league contract with the Minnesota Twins organization.

On July 19, Chacín was granted his release by the Twins without having appeared for the organization as a result of the cancellation of the minor league season because of the COVID-19 pandemic.

[30][31] On January 6, 2021, the same day he became an American citizen, Chacín signed a minor league contract with the New York Yankees organization.

[34] He pitched exclusively out of the bullpen for the first time in his career, posting a 3–2 record and 4.34 ERA with 47 strikeouts in 46 games.

On November 13, 2021, Chacín re-signed with the Rockies on a one-year, $1.25 million major league contract.