By defeating Anastasija Sevastova in the Fed Cup, Serena claimed her first title since her return from maternity leave, marking her 14th different decade with at least one tour-level singles win.
Williams was involved in a high-profile match at the US Open final against Naomi Osaka where she received three code violations, leading to significant media attention and debate.
After giving birth to her daughter and suffering from life-threatening post-delivery complications, Serena made her return to professional tennis at the Indian Wells Masters.
Serena Williams announced her pregnancy, revealing she had won the Australian Open while being approximately eight weeks pregnant.
Williams secured her 23rd Grand Slam singles title at the Australian Open, surpassing Steffi Graf's Open Era record and becoming the player with the most Grand Slam singles titles in the Open Era.
With her 2015 Wimbledon title, Serena held all four major singles titles at once – completing the 'Serena Slam' for the second time – a feat unparalleled in the Open Era.
She won her fifth Wimbledon singles title, and by winning the Olympic gold in singles later that year, she became one of the only female players to achieve a Career Golden Slam.
Serena Williams completed a non-calendar year Grand Slam by winning the Australian Open, holding all four major singles titles simultaneously.
Serena Williams attained the world No. 1 ranking in singles for the first time in her career after winning the Wimbledon Championships.
Serena Williams won her first Grand Slam singles title at the US Open, becoming the second African American woman to win a Grand Slam singles tournament in the Open Era.