Brother and sister Teekatat and Tawisa Hiranmekawanit tied the knot in a traditional ceremony in Ang Thong province, central Thailand.
Parents believe the smiling toddlers were lovers in a previous life but were separated by a terrible tragedy.
They were reincarnated together as twins and have to get married to show ''angels'' that they are in love and be together forever, according to mother-of-the bride and groom Sasi Hiranmekawanit.
''They must get married otherwise one of them will die,'' she said.
''We provided the wedding ceremony according to our belief that in the olden days the boy and girl twins were soulmates but couldn't stay together.
Teekatat and Tawisa are both three years and four months old.
The bride wore a traditional Thai wedding dress with a gold sarong a gold sash.
The groom was dressed in a white shirt, gold pants and a green sash.
The boy even gave a sinsod - payments made by men to the families of the bride - of 22,000 THB (£450) and 30.5g of 23 karat gold.
Villagers and relatives joined the twins and the parents for the ceremony in the Wiset Chai Charn district of Ang Thong.
'As parents we must provide the wedding to let the angels know that the twins are happily in love and will be together forever.
''It is an ancient belief to show the angels they are in love and will never stay apart.''
Despite the formal ceremony, the children won't be married in law.
They are also likely to find and marry their own partners when they get older.