Antonio Alfonseca (/ælfɒnˈseɪkə/; Spanish pronunciation: [anˈtonjo alfonˈseka]; born April 16, 1972) is a Dominican former relief pitcher.

Alfonseca also played for the Florida Marlins (1997–2001, 2005), the Chicago Cubs (2002–2003), the Atlanta Braves (2004), and the Texas Rangers (2006).

He made his debut during the 1997 season, and his rookie campaign saw him win a World Series ring with the Marlins.

[1] While the Marlins denied any connection, shortly afterwards, on March 27, 2002, he was traded, along with Matt Clement, to the Chicago Cubs for Julián Tavárez, Ryan Jorgensen, Dontrelle Willis, and minor league pitcher Jose Cueto.

[4] Alfonseca and his wife Rocío have two sons: Antonio, Jr. and Mark Anthony, and two daughters, Jenitza and Asia.