Williams will partner with Frances Tiafoe with Federer teaming up with Belinda Bencic, his teammates when they won the Hopman Cup earlier this year.

That was Switzerland’s first Hopman Cup since 2001.

Switzerland are the defending champions of the Hopman Cup.

Back to Australia

Williams has not been in action since her controversial in September.

It will also be the first time the 37-year-old will be playing in Australia since she won the 2017 Australian Open while she was still pregnant with her daughter.

"The Aussie fans are always so warm and supportive and the Hopman Cup has always given me a great start to the season, especially ahead of the Australian Open," Williams is quoted to say by

Eight teams will compete in the Hopman Cup and will be split into two groups with teams facing each other in sessions that consist of a men's and women's singles match and a mixed doubles match.

Each team plays the other three in their group, and the top teams in each group then meet in the final.

Teams

Group A

France - Lucas Pouille and Alize Cornet

Spain - David Ferrer and Garbine Muguruza

Germany - Alexander Zverev and Angelique Kerber

Australia - Matt Ebden and Ashleigh Barty

Group B

Great Britain - Cameron Norrie and Katie Boulter

Greece - Stefanos Tsitsipas and Maria Sakkari

Switzerland - Roger Federer and Belinda Bencic

USA - Frances Tiafoe and Serena Williams