Rafael Nadal and Caroline Wozniacki are the International Tennis Federation's world champions for 2010.
It is the second time that Spaniard Nadal has taken the honour, while Wozniacki becomes the first Danish player to receive a senior ITF award.
American twins Bob and Mike Bryan were named men's doubles World Champions for a record seventh occasion, while Gisela Dulko of Argentina and Flavia Pennetta of Italy become women's doubles World Champions for the first time.
Nadal became only the seventh man in history to win a career grand slam when he won the US Open title in September.
The 24-year-old also captured his fifth French Open title and second Wimbledon crown to regain the year-end number one ranking from Roger Federer.
With an Olympic gold medal and two Davis Cup titles to his name, the Spaniard has now won all of tennis's major prizes.
Wozniacki became the fourth-youngest woman after Martina Hingis, Monica Seles and Steffi Graf to earn the year-end number one ranking.
The 20-year-old was the most consistent player on the circuit, earning a tour-high six titles, in Ponte Vedra, Copenhagen, Montreal, New Haven, Tokyo and Beijing.