Martinez is confident the 26-year-old is ready to make an impact in the Premier League.
“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!”
