|Born||28 June 1953|
Deniyaya, Sri Lanka
|Residence||6, Kachchiwatta Road, Magalle, Galle, Sri Lanka.|
|Alma mater||Morawaka Central College|
|Known for||Defeat of Maharaja Rajapaksa|
|Spouse(s)||Meepage Chandra Girlie|
Sumanadasa Tilak Abeygunawardena (known as Sumanadasa Abeygunawardena) is a Sri Lankan astrologer, author and commentator on radio and television news. He also served as the working Director for the National Savings Bank.
Abeygunawardena was the self-proclaimed "Royal Astrologer" to the former Sri Lankan President Mahinda Rajapaksa, and his main work was identifying auspicious timing for the president's political acts. Before calling presidential elections two years ahead of schedule, Rajapaksa consulted Abeygunawardena, who foresaw a "big victory"  not just for a third but also a fourth term in office due to Rajapaksa's "great inborn power". However, Rajapaksa lost the election to his main opponent Maithripala Sirisena. Abeygunawardena initially declined to comment on this wrong prediction and avoided the media, but later said that "even Nostradamus got things wrong."
He was born on 28 June 1953 to a family in Deniyaya Matara District. He is the seventh son of Don Siyadoris Abeygunawardena and Jasin Korale Arachchige Somawathie. Don Siyadoris Abeygunawardena was a village committee Chairman of Morawaka. Sumanadasa Abeygunawardena has three elder sisters, three elder brothers & another two sisters younger to him. He was educated at Morawaka Central College in Deniyaya.
- Sirimanna, Bandula (20 May 2012). "Astrologer-director quits, but NSB chairman defiant". Sunday Times, Sri Lanka. Sunday Times, Sri Lanka. Retrieved 10 January 2015.
- Barry, Ellen (6 January 2015). "As Vote Nears, Astrologer for Sri Lanka's President Faces Ultimate Test of His Skills". New York Times. New York Times. Retrieved 10 January 2015.
- "A fault in his stars?". The Economist. The Economist. 24 November 2014. Retrieved 10 January 2015.
- Barry, Ellen (8 January 2015). "Mahinda Rajapaksa's astrologer Abeygunawardena faces the ultimate test". The Economic Times. The Economic Times. Retrieved 10 January 2015.
- Perera, Amantha (7 January 2015). "Ahead of Sri Lanka election, president in unexpectedly tight race". Al Jazeera. Al Jazeera. Retrieved 10 January 2015.
- Kumar, Nikhil (9 January 2015). "Sri Lanka Looks to Chart a New Course After Ousting Mahinda Rajapaksa". Time. Time. Retrieved 10 January 2015.
- Wijeyesinghe, Chathushika (9 January 2015). ""Yanna Nona Yanna" - MR's astrologer". Daily Mirror, Sri Lanka. Daily Mirror, Sri Lanka. Retrieved 10 January 2015.
- "'Even Nostradamus got things wrong', says astrologer who advised Sri Lanka's president to call election". The Guardian. The Guardian. 13 January 2015. Retrieved 14 January 2015.