Robert Irwin 'Bob' Kreiss (born 30 April 1953) is a former American tennis player who won the Wimbledon Boys' Singles tournament in 1971.

[1] Kreiss won the 1971 Wimbledon Boys' Singles title by beating Stephen Warboys in the final.

[2] He attended UCLA, where he played tennis for UCLA Bruins and earned All-American honors on three occasions, in 1970, 1972 and 1973.

His best result at a Grand Slam tournament was reaching the second round at the 1974 US Open.

During the 1974 Grand Prix season, Kreiss managed to reach two quarterfinals, at the U.S. National Indoor Tennis Championships in Salisbury, Maryland and at the Irish Open in Dublin.