Louise Mai Jansen

At the 2009 FINA World Championships in Rome, Italy, Jansen helped her Danish team (Hjorth-Hansen, Ostergaard, and Friis) to dip under an eight-minute barrier and broke a new record of 7:55.56 in the 4 × 200 m freestyle relay, but finished only in twelfth place overall from the preliminary heats.

At the 2008 Summer Olympics in Beijing, Jansen extended her swimming program to two events: 200-metre freestyle and 4×200-metre freestyle relay. She cleared a FINA B-standard entry time of 2:02.20 (200 m freestyle) from the Danish Open in Copenhagen. In the 200 m freestyle, Jansen raced to fourth place and thirty-fourth overall on the same heat as Athens by exactly one second ahead of Singapore's Lynette Lim in 2:01.30. She also teamed up with Hjorth-Hansen, Micha Østergaard, and Lotte Friis in the 4 × 200 m freestyle relay. Swimming the third leg, Jansen recorded a split of 2:00.31, and the Danish team finished the preliminary heats in tenth overall with a Danish record of 8:00.81.

Jansen made her first Danish team at the 2004 Summer Olympics in Athens. There, she failed to reach the semifinals in any of her individual events, finishing thirty-seventh in the 200 m freestyle, and thirtieth in the 200 m individual medley with respective times of 2:06.06 and 2:27.08.

Louise Mai Jansen (born April 14, 1984) is a Danish former swimmer, who specialized in freestyle and individual medley events. She is an eighteen-time national champion and a Nordic record holder in the freestyle and medley (both 200 m). She is also an eighth-place finalist in the 200 m individual medley at the 2010 European Aquatics Championships in Budapest, Hungary with a time of 2:17.37, just eight seconds off the record set by Julie Hjorth-Hansen in 2009. Jansen is an economics graduate, majoring in mathematics at Copenhagen Business School in Copenhagen.