Reds chief executive David Gill said: "It’s very important to us to engage with our fans around the world and we believe that working with Singha will be another important way of achieving this. We are looking forward to developing the relationship."
At a press conference to announce the deal, United’s commercial director Richard Arnold added: "We're delighted to be introducing Singha to the family of Manchester United sponsors. The brand's premium positioning within both its home market and international territories makes it a perfect partner for us.
"The club constantly seeks to engage with our fans outside of the UK and teaming up with an established global brand of this calibre enables us to do just that. I'm incredibly excited about the prospects that this partnership will bring to the club."
Soravij Bhirombhakdi, deputy managing director of Singha's parent company Boon Rawd Trading International, welcomed the deal, saying: "Matching the Thai brand with a football club that has a worldwide following will broaden our consumer base.
"We are confident that this alliance will write a new chapter in the Singha story for the whole world to read, turning a local brand into the global brand."