Ramanna Nikaya (spelled Rāmañña in Pali, also known as Ramanya Nikaya) is one of the most orthodox Buddhist orders in Sri Lanka. It was founded in 1864 when Ambagahawatte Saranankara, returned to Sri Lanka after being ordained by the Neyyadhama Munivara Sangharaja of Ratnapunna Vihara in Burma. It is one of three Sri Lankan orthodox buddhist orders, along with Siam Nikaya and Amarapura Nikaya.
Ramanna Nikaya is said to be similar to the Thammayut Nikaya order of Thailand. Ramanna Nikaya is currently survived in Thailand, Burma and Sri Lanka.
The Most Ven Napana Premasiri Thera was appointed the Head of the Ramanna Nikaya on 3 September 2012 following the demise of Venerable Weweldeniye Medhalankara Thera aged 103.