Frank Parker is one of the few Americans to win both the French Championships (1948, 1949) and the U.S. Championships (1944, 1945). Parker became the singles champion at Cincinnati, then called the Tri–State Tennis Tournament in 1941 and was a four-time singles finalist (1932, 1933, 1938, 1939). He won the Canadian title in 1938. He was ranked World No. 1 in 1948 by John Olliff of The Daily Telegraph. Writing about Parker in his 1949 autobiography, Bobby Riggs, who had played Parker many times, says “Parker is a tough man to get past. Equipped with a wonderful all-court game, he plays intently and with classic form. His footwork is marvelous. You never see Frankie hitting the ball from an awkward position.”  Jack Kramer, however, writing in his own autobiography, says “…even as a boy [Parker] had this wonderful slightly overspin forehand drive. Clean and hard. Then for some reason, Frankie’s coach, Mercer Beasley, decided to change this stroke into a chop. It was obscene.” It also impaired his game, particularly in preventing him from getting to the net, and Parker dropped in the rankings. A few years later, however, he worked hard to regain his original forehand and, according to Kramer, did indeed greatly improve his stroke. But it was never again as good as it had once been. Frank Parker took part in the 1968 US Open at the age of 52, becoming the oldest player to compete in the US Open.

Between 1937 and 1948 Frank Parker took part in seven Davis Cup ties with the US team and won the Davis Cup in 1937 and 1948. He compiled a Davis Cup record of 12 wins and two losses. In October 1949 Parker signed a one-year contract with Bobby Riggs to become a professional tennis player. Parker was elected to the Wisconsin Athletic Hall of Fame in 1960. Parker was inducted into the International Tennis Hall of Fame in Newport, Rhode Island, in 1966 and into the National Polish American Sports Hall of Fame in 1988. On March 17, 1938 Parker married Audrey Beasley who had previously divorced Parker’s coach Mercer Beasley. She became his adviser and tailored his tennis wardrobe. His wife died in 1971 and in 1979 Parker retired from his position of salesman for a corrugated box company.