James Philip Shellenback (born November 18, 1943) is an American former professional baseball pitcher and coach.

He appeared in 165 Major League games for the Pittsburgh Pirates (1966–1967; 1969), Washington Senators/Texas Rangers (1969–1974) and Minnesota Twins (1977).

In his second pro year, with the 1963 Gastonia Pirates, he won 17 of 20 decisions and posted a 2.03 earned run average.

He also managed the Triple-A Portland Beavers from June 22, 1988, through the end of the season after the resignation of Jim Mahoney.

Late in his career, Shellenback was the pitching coach of the Rookie-level Elizabethton Twins of the Appalachian League for 18 consecutive seasons, from 1994 through his 2011 retirement.