Mathai (Malayalam: മത്തായി) is a given name or surname, usually the Malayalam variant of Matthew, and may refer to:

• Mathai (singer) (Sharon Mathai, born 1992), a contestant on season two of American TV series The Voice
• John Mathai, economist who served as India's first Railway Minister and subsequently as India's Finance Minister
• Mathai Joseph, Indian computer scientist
• Mathai Manjooran, Indian freedom fighter from Kerala
• Mathai Varghese, mathematician and an Australian Research Council Senior Research Fellow at the University of Adelaide
• M.O. Mathai, Special assistant of the Prime Minister of India Jawaharlal Nehru
• Wanjira Mathai (born 1971), Kenyan environmentalist

• Matthew (name)
• Matthai