Peter Alexander Magrini (June 8, 1942 – October 27, 2022) was an American right-handed pitcher in Major League Baseball who played for the 1966 Boston Red Sox.

The 6 ft (1.8 m), 195 lb (88 kg) Magrini attended Santa Clara University, where he struck out Willie Mays during an exhibition game against the San Francisco Giants.

He made his only MLB start in his final game May 9 against the Kansas City Athletics but lasted only three innings and lost his only big-league decision, 6–1.

However, Magrini contributed to Boston's surprise 1967 American League pennant when he was traded with fellow pitcher Ron Klimkowski to the New York Yankees for veteran catcher Elston Howard on August 3, 1967.

Howard helped guide the young Red Sox pitching staff through a five-team pennant scramble and the 1967 World Series.