Michelle Lilienthal is an American distance runner who specializes in the marathon. She competed collegiately in cross country and track for the University of Wisconsin. After graduating, she qualified for four consecutive U.S. Olympic Trials marathons (2008, 2012, 2016, and 2020).

Lilienthal grew up in Iowa City, Iowa, and graduated from Iowa City High School in 2000. She did not start running until her sophomore year but achieved immediate success, winning seven Iowa state championships in cross country and track over her high school career. She also qualified for the 1999 Foot Locker National Cross Country Championship.

At the University of Wisconsin, Lilienthal was an All-Big 10 honoree and competed for the Badgers at multiple NCAA Championships. She graduated in 2004 with a double major in Communications and Spanish.

After graduating from college, Lilienthal moved to Philadelphia and placed third in the 2005 Philadelphia Marathon. The following spring, she clocked a 2:40:23 time at the 2006 Boston Marathon, which placed her second among American women and 16th overall.

At the 2006 Twin Cities Marathon, Lilienthal dropped her time even further to 2:35:51, which qualified her for the 2008 U.S. Olympic Trials Marathon.

In 2007 while living in Minneapolis and representing Minnesota Distance Elite, Lilienthal placed third at the US Half Marathon Championships in Houston with a time of 1:12:46.

At the 2008 US Olympic Trials in Boston, Lilienthal placed 85th of 148 women at 2:48:46.

She had hopes of contending for the Olympic team heading into the 2012 Olympic Trials, but was sidelined with injuries and unable to compete.