Baek Il-Joo (also "Baek Il-Ju", ; born August 14, 1985 in Seoul) is a South Korean swimmer, who specializes in freestyle events. Baek qualified for the women's 200 m freestyle, as South Korea's oldest swimmer (aged 26), at the 2012 Summer Olympics in London, by eclipsing the FINA B-standard entry time of 2:01.24 at the Dong-A Swimming Tournament in Ulsan. She challenged four other swimmers on the first heat at the Olympics, including two-time Olympian Natthanan Junkrajang of Thailand. Baek raced to third place by 0.77 of a second behind Switzerland's Danielle Villars with a third-slowest time of 2:04.32. Baek failed to advance into the semifinals, as she placed thirty-third overall in the preliminary heats.