Maha Vidhwan Rao Sahib Mu Raghava Iyengar (Tamil: மு ராகவ ஐயங்கார்) (1878–1960) was a well known Tamil scholar and researcher of Tamil literature.
Maha Vidhwan Mu Raghava Iyengar (known as M. Raghava Iyengar) was from Manamadurai in Tamil Nadu and lived in the Ramanathapuram area. He was born on July 26, 1878. He was a Tamil scholar and he conducted research on Tamil History and Literature. Notably he worked on establishing the time periods of the old Tamil Poets. His research was also centered around the Alwars.
His father was Sadavadhaanam Muthuswamy Iyengar, a Tamil Poet in the court of Ponnuchami Thevar, the brother of the king of Ramnad, Muthuramalinga Sethupathy. His father wrote a 100 verse Tamil poem மணவாள மாமுனி நூற்றந்தாதி - Manavala Mamuni Nootranthathi on the Vaishnava Saint Manavala Mamuni. He also wrote Nootrettu Thiruppathi Agaval which lists out all the 108 Sri Vaishnava Divya Desams along with Purana Sthalams.
Pandithurai Thevar, who was a nobleman from the Royal family of Ramnad, studied Tamil under his father. When he was young, Mu Raghava Iyengar studied Tamil from Pandithurai Thevar. His cousin R. Raghava Iyengar was a Poet Laureate of the Sethu Samasthanam.
His grand father, Sri Krishna Iyengar was the deputy chief minister under Sri Muthuramalinga Sethupathi or Sri Baskara Sethupathi, Raja of Ramnad. Sri Krishna Iyengar was also known as Chinna Prathani Sri Krishna Iyengar, while, his colleague, Sri Muthirulappa Pilla was the Periya Prathani (Chief of Ministers).
He worked as the head of the Tamil Research department in Thiruvangoor University between 1944-1951. He also worked as a lecturer in the Loyola College, Chennai.
He collaborated with Pandithurai Thevar in promoting Tamil Language. Mu Raghava Iyengar was a leading member of Madurai Tamil Sangam and helped edit the magazine Senthamizh(செந்தமிழ்) between 1905 and 1910. Mu Raghava Iyengar was appointed to the committee that worked on the Tamil-English lexicon/dictionary. This project started with Rev. J.S. Chandler as the Chief Editor and Mu Raghava Iyengar as the Chief Pundit around 1913. The project eventually finished in 1936 under Prof S. Vaiyapuri Pillai (1891–1956). For his scholarly contributions, Mu Raghava Iyengar was granted the title of "Rao Sahib" in 1936 by the government.