Dame Lydia Ko is a New Zealand professional golfer, member of the LPGA Hall of Fame, and the reigning Olympic champion. She first reached number one in the Women's World Golf Rankings on 2 February 2015 at 17 years, 9 months and 9 days of age, making her the youngest player of either gender to be ranked No. 1 in professional golf.
Ko had much success from an early age holding many youngest accolades on the LPGA Tour. Until 2017, she was the youngest ever (age 15) to win an LPGA Tour event. In August 2013, she became the only amateur to win two LPGA Tour events. Upon winning The Evian Championship in France on 13 September 2015, she became the youngest woman, at age 18 years, 4 months and 20 days, to win a major championship. Her closing round of 63 was a record lowest final round in the history of women's golf majors, but she lowered that record with a 62 at the 2021 ANA Inspiration. She had previously won the ANA Inspiration on 3 April 2016 for her second consecutive major championship, where she also became the youngest player to win two women's major championships.
In 2014, Ko was named as one of Time magazine's 100 most influential people.