Tom Trebelhorn (born January 27, 1948) has had a long and varied career in baseball, both as a player and a manager, at the Major League, Minor League, and international levels.
Trebelhorn graduated from Cleveland High School in Portland and played catcher at Portland State University. In the 1970 Major League Baseball draft, he was selected by the Bend Rainbows, a Class A team in the Northwest League affiliated with the California Angels. He played parts of five seasons at the Class A and AA levels before transitioning to coaching. His playing career included time in the minor league systems of the Hawaii Islanders (and their affiliates, the Angels and San Diego Padres) and the Oakland Athletics.
Trebelhorn's managerial career began in the minor leagues. In 1975 and 1976, he managed the Boise A's in the Oakland Athletics organization. Notably, during his time with Boise in 1976, he played a key role in developing Rickey Henderson's base-stealing skills, as Henderson acknowledged in his Hall of Fame induction speech. He also held managerial and coaching positions in the minor league organizations of the Cleveland Indians and Pittsburgh Pirates.
Trebelhorn reached the Major Leagues as the first base coach for the Milwaukee Brewers in 1984. In 1985, he managed the Brewers' Triple-A affiliate, the Vancouver Canadians of the Pacific Coast League, leading them to the league title. He returned to the Brewers in 1986 and became interim manager for the final nine games of the season following George Bamberger's retirement.
He managed the Milwaukee Brewers for five seasons (1986-1991), compiling a 422-397 record. In his first full season in 1987, he led the team to a 91-71 record, earning him Manager of the Year awards from Baseball America and Sports Illustrated. He finished second in the voting for AL Manager of the Year. While his Brewers teams were competitive, they did not capture a division title during his tenure. At the time of his departure, he had the most wins among Brewers managers in franchise history, a record that has since been surpassed.
Trebelhorn was named bench coach of the Chicago Cubs in 1992. He was a finalist for the San Francisco Giants managerial job that off-season but was not selected. He was promoted to manager of the Cubs on October 13, 1993, replacing Jim Lefebvre. His tenure with the Cubs was brief, lasting only the strike-shortened 1994 season, during which the team had a 49-64 record. A notable moment during his time with the Cubs was when, following a particularly bad home losing streak, he fulfilled a promise to answer questions from fans outside a fire station near Wrigley Field. He was fired by new general manager Ed Lynch on October 17, 1994.
Following his time with the Cubs, Trebelhorn returned to the minor leagues, managing the Tri-City Posse of the newly formed Western Baseball League in 1995, leading the team to the league finals. He then moved into front office roles with the Baltimore Orioles, serving as their minor league coordinator of instruction for three years, followed by positions as the team's director of player development and director of organizational instruction. He also served as the Orioles' third base coach (2001-2005, 2006) and bench coach (2005, 2007). He was let go by the Orioles at the end of the 2007 season.
Trebelhorn returned to managing in 2008 for the Class A Salem-Keizer Volcanoes of the Northwest League, a position he held through the 2012 season.
In 2009, he also served as a coach for the Italian National Team in the World Baseball Classic.