"He has taken that opportunity with both hands. Last season he played in the championship-winning team and this week he received an invitation for a Dutch national team exhibition game.
"Ronnie indicated he wanted to move to a foreign league. Wigan were prepared to pay the required transfer fee."
Wigan boss Roberto Martinez believes Wigan have pulled off a coup after finalising the signing of Stam.
"We're extremely excited at Wigan Athletic to welcome Ronnie into our club," Martinez told the club's official website.
"At 26 years of age he is at the peak of his career and, after playing a massive role in FC Twente's championship winning season last campaign, it is fantastic to bring a player of such calibre to our club.
"I'm sure the fans will welcome Ronnie and help him to enjoy his football here, whilst also becoming an important member of the Dutch national side."
Stam added: "It's really exciting for me to be joining the English Premier League, I can't wait to get started now!"