Uthayakumar s/o Ponnusamy (Tamil: உதயகுமார் பொன்னுசாமி) (born 7 November 1961) is a Malaysian lawyer of Tamil origin. He is the older brother of P. Waytha Moorthy, HINDRAF (the Hindu Rights Action Force) lawyer who headed a team of lawyers to file a class action suit against the United Kingdom for "abandoning minority Indians to the mercy of majoritarian Malay rule while granting independence on August 31, 1957". Although Uthayakumar is only a legal advisor of HINDRAF, a coalition of several non-governmental organisations, he is regarded as the de facto leader of HINDRAF.