is an American former soccer player who played as a midfielder. He appeared for MetroStars, San Jose Earthquakes, Houston Dynamo and Columbus Crew SC in the United States, Eintracht Frankfurt in Germany, and Stabæk in Norway. Clark also appeared for the United States national team.

A native of Atlanta, Clark played two years in college at Furman before being drafted second overall in the 2003 MLS SuperDraft by MetroStars. After two seasons and nearly 100 appearances, he was traded to San Jose Earthquakes. The franchise moved from San Jose to Houston for the 2006 season, becoming the Houston Dynamo, and Clark followed along. He spent four seasons with the Dynamo, helping the club win two MLS Cups, before departing for Europe. Clark spent three years in Europe, playing for Eintracht Frankfurt and Stabæk, before returning to the United States and the Dynamo midway through the 2012 Major League Soccer season. He spent the next six years in Houston, departing at the end of 2017 with 304 appearances for the Dynamo across his two spells. Clark signed as a free agent with Columbus Crew SC, spending his final two professional seasons with the Crew before retiring following the 2019 season.

At international level, Clark appeared for the United States at the 2003 FIFA World Youth Championship. He earned his first senior cap in October 2005 against Panama, and went on to score three goals in 34 caps for his country. Clark represented the United States at two CONCACAF Gold Cups, helped the U.S. to the final of the 2009 FIFA Confederations Cup, and played at the 2010 FIFA World Cup. He earned his final senior cap in January 2012.