Nishantha Ranatunga is a former Sri Lankan cricketer who played two ODIs for Sri Lanka during the Sharjah tour in 1993. An all-rounder who has played more than 200 first class matches for three sports clubs,  Nishantha is the brother of former Sri Lanka captain and Parliamentarian Arjuna Ranatunga, former Western Province Chief Minister Prasanna Ranatunga, Sanjeeva Ranatunga and Dammika Ranatunga.

Ranatunga is also the secretary of Sri Lanka Cricket and the CEO of CSN television network. He came under severe criticism for holding two conflicting positions at the same time. CSN is a sports channel that got cricket broadcasting rights from Sri Lanka Rupavahini Corporation.  

He also served as the secretary of the cricket interim-committee that was in charge of the cricket board when stadiums were built and renovated for the ICC Cricket World Cup 2011.Following the term of the interim committee, Sri Lanka Cricket ran into bankruptcy.

At one point, Ranatunga was the Director General of the state-owned Sri Lanka Rupavahini Corporation.

In January, 2012, he was elected uncontested as the secretary of the cricket board.