The 1985 Southeast Asian Games (Thai: กีฬาแห่งเอเชียตะวันออกเฉียงใต้ 1985, romanized: Kila haeng echeiy tawan oak cheing tai 1985), officially known as the 13th Southeast Asian Games, was a Southeast Asian multi-sport event held in Bangkok, Thailand from 8 to 17 December 1985.

This was the fourth time Thailand hosted the games and its first time since 1975. The country had previously hosted the 1959, 1967 and the 1975 editions, at the time when the games were then known as the Southeast Asian Peninsular (SEAP) Games. The games was opened and closed by Bhumibol Adulyadej, the King of Thailand at the Suphachalasai Stadium.

The final medal tally was led by hosts Thailand, followed by Indonesia and the Philippines. Several Games and National records were broken during the games. With little or no controversies at all, the games were deemed generally successful with the rising standard of competition amongst the Southeast Asian nations.