Wat Mahathat (; "Temple of Great Relic" or "Temple of Great Reliquary") is the common short name of several important Buddhist temples in Thailand. The name may refer to:
Wat Mahathat Wat Mahathat (Fak Tha, Uttaradit), Fak Tha District, Uttaradit Province Wat Mahathat (Nakhon Phanom), Nakhon Phanom Province Wat Mahathat (Ayutthaya), Phra Nakhon Si Ayutthaya Province Wat Mahathat (Phetchaburi), Phetchaburi Province Wat Mahathat (Phichai, Uttaradit), Phichai District, Uttaradit Province , Ratchaburi Province Wat Mahathat (Sukhothai), Sukhothai Province Wat Mahathat (Yasothon), Yasothon Province Wat Mahathat Yuwaratrangsarit, Bangkok Wat Phra Mahathat, Nakhon Si Thammarat Province Wat Phra Si Mahathat, Bangkok Wat Phra Si Rattana Mahathat Wat Phra Si Rattana Mahathat (Lop Buri), Lop Buri Province Wat Phra Si Rattana Mahathat, Phitsanulok Province Wat Phra Si Rattana Mahathat (Ratchaburi), Ratchaburi Province Wat Phra Si Rattana Mahathat, Si Satchanalai, Sukhothai Province Wat Phra Si Rattana Mahathat (Suphan Buri), Suphan Buri Province