Antonio José Castillo Jiménez (born March 1, 1963) is a Venezuelan former relief pitcher in Major League Baseball (MLB), who played for the Toronto Blue Jays, Atlanta Braves, New York Mets and Chicago White Sox.

Castillo played in four career playoff games, all with Toronto in 1993, posting a 1–0 record with a 5.06 ERA, and helping the Jays win the 1993 World Series.

On September 3, Castillo earned his first career victory, pitching 2+1⁄3 innings, allowing no hits and walking two batters, while striking out one in a 7–4 win over the Texas Rangers.

In 1990, Castillo made his first career start on July 24 in the second game of a doubleheader against the Houston Astros, and allowed two runs in 4+1⁄3 innings pitched, as he had a no-decision in a 9–8 victory.

Castillo began the 1991 season in the Braves bullpen, where he went 1–1 with a 7.27 ERA in seven games before being traded with Joe Roa to the New York Mets for Alejandro Peña on August 28.

On January 22, 1992, the Mets traded Castillo and Mark Carreon to the Detroit Tigers in exchange for Paul Gibson and minor leaguer Randy Marshall.

Castillo made 51 appearances as part of the bullpen, going 3–2 record with a 3.38 ERA in 50+2⁄3 innings pitched en route to the 1993 American League East title.