Jayson Julio Aquino Félix (born November 22, 1992) is a Dominican professional baseball pitcher for the Baltimore Orioles of Major League Baseball (MLB).
Aquino signed with the Colorado Rockies as an international free agent on July 2, 2009. He spent his first professional season with the Dominican Summer League Rockies in 2010, posting a 4–3 win–loss record, a 1.02 earned run average (ERA), and 59 strikeouts in 61 2⁄3 innings pitched. He also played the 2011 season with the DSL Rockies, and pitched to an 8–2 record, 1.30 ERA, and 80 strikeouts in 89 2⁄3 innings. In 2012, Aquino pitched for both the DSL Rockies and the Rookie Grand Junction Rockies, posting a combined record of 10–1, a 1.66 ERA, and 110 strikeouts in 108 1⁄3 innings.
2013 saw Aquino promoted to the Short-Season A Tri-City Dust Devils, and later the Class-A Asheville Tourists. In 14 starts comprising 87 innings, he would go 0–10 with a 4.34 ERA and 73 strikeouts. He was added to the Rockies' 40-man roster on November 20, 2013. In 2014, Aquino played with the Advanced-A Modesto Nuts and the Double-A Tulsa Drillers, posting a combined 5–10 record, a 5.13 ERA, and 83 strikeouts in 107 innings pitched. He was designated for assignment by the Rockies on January 30, 2015, and traded to the Toronto Blue Jays for Tyler Ybarra on February 4, 2015. On March 8, Aquino was optioned to the Double-A New Hampshire Fisher Cats. He was designated for assignment on May 5. On May 10, he was traded to the Pittsburgh Pirates for cash considerations. The Pirates designated Aquino for assignment on July 22. He was claimed by the Cleveland Indians a few days later.
Aquino was claimed off waivers by the St. Louis Cardinals on December 9, 2015. He was traded to the Baltimore Orioles on April 7, 2016. He pitched for the Bowie Baysox of the Class AA Eastern League before he was promoted to the major leagues on July 4, 2016.