Sedapatti R. Muthiah (4 October 1945 – 21 September 2022) was an Indian politician of the Dravida Munnetra Kazhagam.

R. Muthiah entered politics as Student Leader in Dravida Munnetra Kazhagam (DMK) in the early days of Dravidian Movement.

Muthiah was chosen to stand from Sedapatti constituency under which hometown comes based on the support he had as a Student Leader in 1977.

Due to his continued victory in all elections he became a household name of the region and hence was fondly called as "Sedappattiyar" by people of the area, which later became his name.

In the Twelfth Lok Sabha he served as a Union Minister for Surface Transport in Atal Bihari Vajpayee cabinet.

During the Twelfth Lok Sabha Vajpayee called for a Vote of Confidence after AIADMK had withdrawn support to the government.

[3] This led the AIADMK leader to think Muthiah plotted to save the Vajpayee Government and expelled him from the party.

Political critics were surprised at how the technical error led to the fall of a soft-spoken veteran politician.

He proved his power in his younger son's marriage which was presided over by M. Karunanidhi, then Chief Minister of Tamil Nadu.

M. Manimaran, younger son of Sedapatti Muthiah is currently the Secretary of Madurai South District, DMK party.

Sedapatti Muthiah's popularity and Manimaran's recent performance along with the larger families in nearby villages and Mukkulathor community has gained him fame.