[3][4] Seelalankara entered priesthood at age 22 and became a student of the Matara Walpita Aranya Senadhipathi Badulla Pannalankara Thero.

He was ordained as Millane Siriyalankara Thero and later served as the Chief Incumbent of the Dimbulagala Viharaya.

[8] On 12 June 1979, Seelalankara was appointed as the Chief Sanghanayaka of the North and East Tamankaduwa Provinces.

[9] On 26 May 1995, Seelalankara was shot and killed by the Liberation Tigers of Tamil Eelam when he was on his way to visit a farm belonging to the temple.

Sri Lanka Post issued a postage stamp on July 21, 2005, to commemorate his valuable service to the nation.