Calvin Gregory Maduro (born September 5, 1974) is an Aruban former professional baseball player. He played five years in Major League Baseball between 1996 and 2002. For most of the 2010s, he was a scout for the Baltimore Orioles.

Maduro was sent from the Orioles to the Phillies on September 3, 1996, in a transaction that began when Todd Zeile and Pete Incaviglia were acquired by Baltimore on August 29 and ended when Garrett Stephenson also went to Philadelphia on September 4.^[1][2][3] He played for the Phillies from 1996 to 1997 and the Orioles from 2000 to 2002.^[4] Maduro also represented the Netherlands at the 2004 Summer Olympics in Athens where he and his team finished sixth. In those years he played for the Dutch major league club HCAW.

In 2005, Maduro was named the pitching coach for the Aberdeen IronBirds of the New York–Penn League, an Orioles farm team. He spent three seasons there, then two more seasons with the Gulf Coast Orioles before becoming a scout in 2010. After 10 years in the Orioles organization, he became the pitching coach for the Gulf Coast Twins in 2021.^{[citation needed]}

After the 2003 season, he was decorated as a Knight in the Order of Orange-Nassau, along with fellow Aruba-born baseball players Eugene Kingsale and Sidney Ponson.