Sean Patrick Gilmartin (born May 8, 1990) is an American professional baseball pitcher in the Baltimore Orioles organization. He previously played in Major League Baseball (MLB) for the New York Mets. Gilmartin was the 28th overall selection in the 2011 Major League Baseball draft by the Atlanta Braves. Prior to beginning his professional career, Gilmartin attended Florida State University, and was an All-American pitcher for the Seminoles baseball team.

Gilmartin was born in Moorpark, California to Dr. Paul J., a chiropractor, and JoAnna Gilmartin.^[1] He attended Crespi Carmelite High School in Encino, California. After graduating from high school, the San Diego Padres selected Gilmartin in the 31st round of the 2008 Major League Baseball Draft. Gilmartin opted not to sign with San Diego, instead attending college.^[2]

Gilmartin enrolled at Florida State University in 2009, receiving a scholarship to play college baseball for the Florida State Seminoles baseball team. As a junior in 2011, Gilmartin was named an All-American by Baseball America.^[3]

Gilmartin was drafted by the Atlanta Braves in the first round, with the 28th overall selection, of the 2011 Major League Baseball Draft.^[4] He signed with the Braves, receiving a $1,134,000 signing bonus.^[2] In the Atlanta farm system Gilmartin played with the Gulf Coast League Braves, Rome Braves, Mississippi Braves, and the Gwinnett Braves.

Prior to the 2012 season, Gilmartin was ranked as the Braves fifth best prospect by Baseball America.^[5] Gilmartin was invited to spring training in 2013, but did not make the team.^[6] He played for the Gwinnett Braves of the Class AAA International League, though his performance was limited by shoulder injuries.^[7]

After the 2013 season, the Braves traded Gilmartin to the Minnesota Twins for Ryan Doumit on December 18, 2013.^[8][9] He pitched for the New Britain Rock Cats and the Rochester Red Wings in 2014.

Gilmartin with the Rock Cats finished 7-3, 3.12 ERA in 12 games in 72 innings pitched with 74 strikeouts with a WHIP of 1.278 while giving up 76 hits, 30 runs (25 of them earned), 2 home runs, and 16 walks.

With the Red Wings he finished 2-4, 4.28 ERA in 14 games in 73.2 innings pitched with 59 strikeouts with a WHIP of 1.317 while giving up 69 hits, 39 runs (35 of them earned), 7 home runs, and 28 walks.

During the 2014 Winter Meetings, the New York Mets selected Gilmartin from the Twins in the Rule 5 draft on December 11.^[10] Gilmartin competed to make the Mets' Opening Day 25-man roster as a relief pitcher and got a spot in the bullpen.^[11] Gilmartin made his major league debut on April 10 against the Braves in a 5-3 loss, getting Nick Markakis to groundout and striking out Freddie Freeman to end the seventh inning.^[12]

On June 14, Gilmartin got his first win against the Braves, holding Atlanta scoreless through both the fifth and the sixth innings.

He faced seven batters, walking one and striking out three, in a 10-8 Mets' victory.^[13] On July 19, he got his first major league hit, a bloop single into left field off Carlos Martínez, in his first major league at-bat, in the sixteenth inning against the St. Louis Cardinals.^[14] Gilmartin pitched three scoreless innings, in the fourteenth, fifteenth and the sixteenth innings, giving up 1 hit, 2 walks and getting 4 strikeouts while facing 12 batters.^[15]

After the Mets clinched the National League East division title, Gilmartin made his first major league start on October 1 against the Philadelphia Phillies at Citizens Bank Park, throwing five innings. He struck out three batters and allowed two runs and three hits, throwing 44 of 70 pitches for strikes. He retired 11 of the first 12 batters he faced in a game that lasted just 2 hours, 23 minutes.^[16] The two runs he allowed came on Darin Ruf's two-run home run in the 4th inning.^[17] However, the Mets lost the game by a score of 3-0.^[18]

When the Mets made the playoffs, Gilmartin was not on the roster for the Division Series, but was added to the roster for the Championship Series, replacing Erik Goeddel.^[19] Gilmartin did not appear in the championship series. Gilmartin appeared in game two of the World Series in the top of the eighth inning, retiring the two batters he faced. Gilmartin finished the 2015 regular season with a record of 3-2, and a 2.67 ERA in 50 games (one start) in 57 1⁄3 innings pitched, with 54 strikeouts and a WHIP of 1.186, while giving up 50 hits, 17 runs, two home runs, and 19 walks.

Gilmartin was cut from the roster heading into the 2016 season as veteran reliever Jim Henderson beat him out for the last job in the bullpen during spring training.^[20] Gilmartin was recalled to the Mets on May 12, replacing an injured Wilmer Flores on the roster. With the AAA 51s, Gilmartin had pitched 32.2 innings, sporting a 4-1 record with a 2.48 ERA and 1.13 WHIP.^[21] Days later, Gilmartin was sent back down to the 51s to make room for Matt Reynolds on the roster.^[22] Gilmartin had pitched five scoreless innings in two games during his brief call-up, giving up two hits and striking out five batters.

On June 11, the Mets designated Gilmartin for assignment.^[23]

On June 11, 2017, Gilmartin was claimed off waivers by the St. Louis Cardinals.^[24][23] He was outrighted to AAA on September 1, 2017. He was released on July 2, 2018.

On July 12, 2018, Gilmartin signed a minor league deal with the Baltimore Orioles. He was called up to the majors on August 11, 2018. He was outrighted off the roster following the season and elected free agency on November 1. The following day, he re-signed with the Orioles on a minor league contract.^[25]

After starting the 2019 season in the minor leagues for the Orioles, Gilmartin had his contract selected to the majors on June 17, 2019.

Gilmartin was designated for assignment on June 25, following the acquisition of Tayler Scott.

Gilmartin throws four pitches: a fastball, a curveball, a changeup and an occasional slider only to left handed hitters.^[26]

Gilmartin is married to Republican National Committee spokeswoman Kayleigh McEnany.^[27] His brother Michael was drafted by the Oakland Athletics from Wofford College as an infielder in the 27th round of the 2009 MLB draft.^[28][29]