The 59-year-old left his role as QPR manager at the end of the season as his contract expire, with Michael Beale replacing him. Warburton was in charge at the club for three years, after managerial spells before that at Brentford, Rangers and Nottingham Forest.
He has taken a step away from the hot seat himself though and joins David Moyes’ coaching staff, adding a wealth of experience to the club as a replacement for Stuart Pearce who stepped away from his role last month. He joins the existing coaching team of Billy McKinlay, Paul Nevin, Kevin Nolan and Xavi Valero.
“It’s a huge privilege to be joining West Ham United to work as part of David Moyes’ backroom staff,” Warburton told West Ham’s official website.
“West Ham have made incredible progress in recent seasons, continually making forward strides to move the Club in a positive direction.
“I am excited about coming in and adding my own experience and know-how to what is an incredibly strong coaching team here.”
Moyes added: “I’m really pleased to welcome Mark to West Ham United. He’s a really valuable addition to the backroom team, in the wake of Stuart Pearce leaving us at the end of last season.
“Mark is hugely experienced and has a fine track record, having managed at a number of Club’s over the course of his career.
“I’m excited about adding him to my coaching set-up as one of my assistants.”