Tamarine Tanasugarn and Sonchat Ratiwatana are the defending champions of the Mixed Doubles competition of the 2011 Southeast Asian Games. Tanasugarn decided not to participate. Ratiwatana partnered with Varatchaya Wongteanchai but the pair lost in the quarterfinals to Denise Dy and Treat Conrad Huey. Dy and Huey eventually won the title by beating Jessy Rompies and Christopher Rungkat 4–6, 6–3, [10–6] in the final.