Thomas Samuel "Tom" Okker (born 22 February 1944) is a former Dutch tennis player. He was ranked among the world's top 10 singles players for seven consecutive years, 1968–74, reaching a career high of World No. 3 in 1969. He also was ranked World No. 1 in doubles in 1969.

Okker was the Dutch champion from 1964 through 1968. In 1968, his first year as a professional, he won in singles and in doubles (with Marty Riessen) at the Italian Open. At Wimbledon, Okker reached the quarterfinals in 1968 and the semifinals in 1978. He achieved his best result in a Grand Slam tournament at the 1968 US Open, where he competed as a registered player, an amateur allowed to compete for prize money but playing under the control of their national associations. Okker reached the final after defeating Pancho Gonzales in the quarterfinal and Ken Rosewall in the semifinal. He lost the final to American Arthur Ashe in five sets, 12–14, 7–5, 3–6, 6–3, 3–6. Okker turned professional in February 1969 when he signed a four-year contract with the Lamar Hunt's World Championship Tennis.

Okker won 31 singles titles. He also was the runner-up in 24 singles tournaments.

Okker is also among the most successful men's doubles players of all time. Okker won two Grand Slam doubles titles, the US Open in 1976 (with Riessen) and the French Open (with John Newcombe) in 1973. In total, Okker won 78 doubles events, a record that was finally broken by Todd Woodbridge in 2005. Okker's other doubles titles include the 1973 Italian Open, 1973 London Grass Courts (with Riessen), 1973 Spanish Open (with Ilie Năstase), 1975 Opel International (with Arthur Ashe), and 1978 WCT World Doubles (with Wojtek Fibak).

...
Wikipedia