Marek Twardowski (born 6 October 1979 in Białystok) is a Polish sprint canoeist who has competed since the late 1990s. He won fifteen medals at the ICF Canoe Sprint World Championships with two golds (K-1 500 m: 2006, K-2 500 m: 1999), nine silvers (K-2 200 m: 2002, 2003, 2006; K-2 500 m: 2002, 2005; K-2 1000 m: 1999, K-4 200 m: 1999, K-4 1000 m: 2006, 2007), and four bronzes (K-1 500 m: 2007, K-2 200 m: 1999, 2005; K-4 1000 m: 2007).
Twardowski also competed in three Summer Olympics, earning his best finish of fourth in the K-2 500 m event at Athens in 2004.
Nicknamed Twardy, he is 1.82 m (6'0) tall and weighs 85 kg (187 lbs). Twardowski is a member of the Sparta Augustów club where he is coached by Andrzej Siemion.
On 9 July 2008 he was named the Polish national flag bearer for the 2008 Summer Olympics in Beijing.