Kenneth Purvis MacKenzie (March 10, 1934 – December 14, 2023) was a Canadian relief pitcher in Major League Baseball.

He played with the Milwaukee Braves (1960–61), New York Mets (1962–63), St. Louis Cardinals (1963), San Francisco Giants (1964), and Houston Astros (1965).

MacKenzie signed with the Braves in 1956 and began working his way through the club's farm system, becoming a relief specialist in 1959, his third professional baseball season.

Manager Casey Stengel said of him: "He's a splendid young fella with a great education from Yale University.

MacKenzie recorded eight wins, five losses, and four saves, with a 4.96 earned run average over 76 games pitched for the Mets.