Maharajapuram Viswanatha Iyer (Tamil: மகாராஜபுரம் விசுவநாதையர்; 1896–1970) was one of the great Indian Carnatic vocalists.

Palghat Rama Bhagavathar was a fellow student under Umayalpuram Swaminatha Iyer.

His has been hailed as the success of 'kalpana sangeetha', music rich with imagination in raga elaboration and swara singing, a specialty of his.

His prominent disciples include Semmangudi Srinivasa Iyer, Mannargudi Sambasiva Bhagavatar, and his own son Maharajapuram Santhanam.

[3] He acted in a Tamil movie "Bhaktha Nandhanar" released on 1 January 1935 as the landlord Vedhiyar.