Wat Mahathat (Thai: วัดมหาธาตุ; "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
- Wat Mahathat (Ratchaburi) , 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 Rattana Mahathat
- Wat Phra Si Rattana Mahathat (Bangkok), Bangkok
- 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 (Sukhothai), Sukhothai Province
- Wat Phra Si Rattana Mahathat (Suphan Buri), Suphan Buri Province