R. Mahadevan (born 10 June 1963) is a Judge of Supreme Court of India.

He is the former Judge of Madras High Court where he has also served as the Acting Chief Justice.

After completion of law degree he enrolled in the bar council of Chennai in the year 1989.

Civil, criminal and writ sides with specialization in indirect taxes, customs and Central Excise matters are the areas where he had rich practice experience for more than 25 years.

On 18 July 2024, he was appointed as a Judge of Supreme Court of India.