The 28 year old actor actor was reportedly offered the role last week by Marvel Studios, but contract negotiations were delayed until today.
Evans contract means he will star in the upcoming 'The First Avenger: Captain America' and he will feature in several more Marvel movies, including The Avengers.
Captain America is expected to begin production in London this summer.
UPDATE: Official Marvel press release:
Marvel Studios has officially confirmed that Chris Evans will star as Captain America in the studio's highly anticipated movie THE FIRST AVENGER: CAPTAIN AMERICA directed by Joe Johnston from a script penned by Christopher Markus & Stephen McFeely.
Marvel Studios' Kevin Feige will produce THE FIRST AVENGER: CAPTAIN AMERICA. Alan Fine, Stan Lee, David Maisel, Stratton Leopold and Louis D'Esposito will executive produce. The film will be released in the US on July 22, 2011 and distributed by Paramount Pictures.
THE FIRST AVENGER: CAPTAIN AMERICA will focus on the early days of the Marvel Universe when Steve Rogers volunteers to participate in an experimental program that turns him into the Super Soldier known as Captain America.
Chris Evans will next star in Sylvain White's THE LOSERS. He will also star in Edgar Wright's SCOTT PILGRIM VS. THE WORLD. He recently wrapped production on PUNCTURE and he will soon start production on WHATS YOUR NUMBER. Evans previous credits include starring as Johnny Storm in the FANTASTIC FOUR Films, Danny Boyle's SUNSHINE and David Ayer's STREET KINGS.
In addition to THE FIRST AVENGER: CAPTAIN AMERICA, Marvel Studios will release a slate of films based on the Marvel characters including the highly anticipated sequel, IRON MAN 2, starring Robert Downey Jr. and Gwyneth Paltrow on May 7, 2010, THOR on May 6, 2011, and THE AVENGERS on May 4, 2012.
Evans is represented by CAA, 3 Arts Entertainment and his attorney at Stone, Meyer, Genow, Smelkinson & Binder.