Jeff Borowiak (born September 25, 1949 in Berkeley, California) is a former tennis player from the United States, who won five singles and three doubles titles during his professional career. He played number one singles on one of the greatest collegiate tennis team of all time for the UCLA Bruins. Haroon Rahim played number two singles, Jimmy Connors played at number three. Borowiak and Connors were NCAA champions, while Rahim remains the youngest player ever to represent his country in the Davis Cup competition. Others on the team included Modesto Vazquez, Jeff Austin, Elio Alvarez, and the Kreiss Brothers.

The right-hander reached his highest singles ATP-ranking on December 31, 1977, when he became the World No. 25.

Borowiak was inducted into the Intercollegiate Tennis Association (ITA) Hall of Fame.

Personal

Borowiak is also an accomplished musician, mastering the flute and the piano. He was also indirectly involved in the formation of the group Metallica when he invested in his friend and Danish fellow player Torben Ulrich's son band Lars Rocket, which later became Metallica.