Marcin Lewandowski born 13 June 1987 is a Polish middle-distance runner who specializes in the 800 metres. His personal best is 1:43.29 minutes, achieved in August 2013 in Zürich.
Lewandowski is coached by his brother, Tomasz.
Lewandowski finished fourth at the 2006 World Junior Championships, won the 2007 European U23 Championships, and won the silver medal at the 2009 European U23 Championships behind countryfellow Adam Kszczot.
Lewandowski competed at the 2008 Olympic Games without reaching the final, but then finished sixth at the 2009 European Indoor Championships and eighth at the 2009 World Championships. His first medal of 2010 was a bronze, as he was third behind Yuriy Borzakovskiy and Michael Rimmer at the 2010 European Team Championships. Lewandowski won the 800 m at the 2010 European Athletics Championships and took the silver medal behind David Rudisha at the 2010 IAAF Continental Cup.
He improved his indoor best to 1:46.17 minutes at the Sparkassen Cup in February 2011, coming third.
In the 2012 Summer Olympics from London, he just failed to make it to the final of the 800 metres.