Grace Sari Ysidora (born 11 May 1993) is a female Indonesian professional tennis player. She made her debut as a professional in 2008, aged 15, at an ITF tournament in Jakarta. In that year, she reached the final of the women's doubles of the inaugural 2008 Garuda Indonesia Tennis Masters, partnered by Septi Mende. They were defeated by Ayu-Fani Damayanti and Liza Andriyani.
She took part in the girls' competitions at the 2009 French Open, 2009 Wimbledon Championships, 2009 US Open, 2010 Australian Open, 2010 French Open, and 2010 Wimbledon Championships. Her greatest success was in reaching Round 3 at the Australian Open in the girls' singles competition.
She was Indonesia's sole representative in the sport of tennis at the 2010 Summer Youth Olympics.
She first won an ITF event in 2011. In that year, she also won two medals at the 2011 Southeast Asian Games in Palembang: the bronze in the Mixed Doubles event, and the silver in the Team event.