- ITF news
Djokovic and Serena on top of the world
Djokovic, who successfully defended his Australian Open title, wins the award for a second year after topping the world rankings for successive seasons.
"I am proud to have been named ITF World Champion for the second successive year," Djokovic said.
"It was very difficult to follow up such a successful season in 2011, but it was extremely satisfying to win another grand slam title, reach two other major finals and finish the year at No. 1."
Williams, meanwhile, is named women's champion for the third time despite ending the season at world No. 3.
The American added a further two grand slam titles to her impressive CV after winning Wimbledon and the US Open. She also won gold at the London 2012 Olympics and ended the year with victory at the WTA Championships.
She said: "It means a lot to be named ITF World Champion for the third time. It has been such an amazing experience this year to win the Olympics and two grand slam tournaments, and I look forward to having an awesome 2013."
American brothers Bob and Mike Bryan were named men's doubles champions for the ninth time, while the women's award went to Italian pair Sara Errani and Roberta Vinci.