Angelique Kerber (German: [ʔan.d͡ʒɛˈliːk ˈkɛɐ̯bɐ] ^ⓘ; born 18 January 1988) is a German former professional tennis player. She was ranked as the world No. 1 in women's singles by the Women's Tennis Association (WTA) for 34 weeks, including as the year-end No. 1 in 2016. Kerber won 14 WTA Tour-level singles titles, including three majors at the 2016 Australian Open, the 2016 US Open, and the 2018 Wimbledon Championships. She also won a silver medal in women's singles at the 2016 Rio Olympics.

Kerber made her professional debut in 2003 and began her rise to prominence upon reaching the semifinals of the 2011 US Open as the world No. 92. An accomplished left-handed player, Kerber first cracked the top 5 in the rankings in 2012 and would eventually become world No. 1 on 12 September 2016, becoming the 22nd and oldest player to achieve the top ranking. Following a maternity leave, Kerber retired from the sport after the 2024 Paris Olympics.

Kerber was born on 18 January 1988 in Bremen to Polish-German parents Sławomir Kerber, from Poznań, and Beata (née Rzeźnik), who is also her manager. She has one sister, Jessica. She grew up in Kiel, where her family stayed in an apartment in a training academy where her parents work, and started playing tennis at age three, eventually joining the junior circuit. Although born right-handed, Kerber plays left-handed.

Kerber made her first attempt to qualify for a WTA tournament in January 2005, at the Auckland Open, falling to Janette Husárová in the final round. In 2007, she made her Grand Slam main-draw debut at the French Open where she lost to 13th seed Elena Dementieva in the opening round. Shortly after, she appeared in the main draw of a WTA tournament for the first time, in Birmingham, where she reached the third round, losing to fifth seed Marion Bartoli, who was the eventual runner-up at Wimbledon that year. The week after Birmingham, she reached her first main draw quarterfinal at the Rosmalen Open where she was beaten by eventual champion Anna Chakvetadze, and then fell to Chakvetadze once more, in the first round of Wimbledon. At the US Open, Kerber drew Serena Williams in the first round and lost in straight sets. Kerber achieved her first top-100 season finish in 2007, at world No. 84. She won eight titles on the ITF circuit from 2004 to 2007.

Kerber achieved her first Grand Slam victory in 2008 at the Australian Open by defeating Maret Ani, before losing to 25th seed Francesca Schiavone. She also made the third round at Indian Wells where she lost to sixth seed Bartoli. Kerber did not progress much that year after that, besides winning a further two ITF titles. Her struggles would continue in 2009 as she managed just three wins in WTA main draws. She did qualify for the US Open that year, where she made the second round. She also won her 11th and final ITF title that year. She finished 2008 and 2009 respectively ranked barely outside the top 100, at No. 108 and No. 106, respectively.

In 2010, Kerber qualified for the Australian Open where she reached the third round of a major for the first time, losing to third seed Svetlana Kuznetsova in a close three-setter, from a set up. She then reached her maiden WTA final, in Bogotá, finishing runner-up to home star Mariana Duque Mariño, having upset top-seed Gisela Dulko in the semifinals. Kerber proceeded to reach two other quarterfinals that year, in Fes and Copenhagen, and also reached the third round of Wimbledon, where she defeated Sania Mirza and upset 13th seed Shahar Pe'er before losing to Jarmila Groth. At the end of the year, she made the third round in Beijing where she lost to Li Na, and capped off her season with a semifinal run in Luxembourg. She ended the year ranked No. 47.

Kerber did not win back-to-back matches in the first seven months of 2011 except once, at her first tournament of the year, in Hobart. At Wimbledon, she lost to youngster Laura Robson in the first round. In Dallas, the week before the US Open, she recorded a semifinal run, where she lost to Aravane Rezaï.

Kerber entered the US Open ranked world No. 92, and passed the first hurdle with a win in three sets over Lauren Davis in three sets. Next, she faced 12th seed Agnieszka Radwańska and pulled off a shock three-set victory before going on to beat both Alla Kudryavtseva and Monica Niculescu to reach her maiden Grand Slam quarterfinal. There, Kerber surprised multiple-time quarterfinalist here Flavia Pennetta in three sets to advance to the semifinal, where she lost to ninth seed and eventual champion Samantha Stosur in three sets. Kerber reached a new career-high ranking of world No. 34 after the tournament.