She was educated at Embilipitiya Maha Vidayala and Ferguson High School, Ratnapura. She married Athula Senanayake, an entrepreneur who is the son of Stanley Senanayake, a former Inspector General of Police and Maya Senanayake, the daughter of the founder of Nalanda college P. de S. Kularatne. They have three children Kanishka, Thisakya and Radhya.
Her professional life has been devoted to promoting Sri Lanka and particularly Sri Lankan trade to the world. She works for the rights of women and adolescents in her country and as a United Nations Population Fund Goodwill Ambassador. Through the National Youth Services Council she promoted reproductive health services for young people and for migrant women workers in Sri Lanka's Free Trade Zone. Senanayake has worked with the private sector to provide reproductive health services to employees of private companies in Sri Lanka and recently starred in a film about reproductive health. Through her popular daytime television program Eliya she has become an icon for women's and children's causes in Sri Lanka.
Diplomatic work
In 1998 she was appointed as a United Nations Population Fund Goodwill Ambassador. Senanayake was appointed as Sri Lankan High Commissioner to Malaysia in 2002, which she held until 2004.
Politics
A major opposition activist, she is the Chief Organiser for the Colombo West Electorate of the United National Party. She was elected to the Western Provincial Council in 2009, topping the preferential votes list in Colombo District by obtaining 80,884 votes. There, she served as the Leader of the Opposition until being elected to the parliament in 2010 securing the fourth place in the UNP list with 66,357 preferences. In Parliament, she has raised several prominent issues such as violence against women and children, chauvinism and socio-cultural and socio-economic problems affecting Sri Lanka. The UK-based Guardian in its edition of 14 June 2013 published an article titled, "Top 10 sexist moments in politics: Julia Gillard, Hillary Clinton and more" which described an encounter in 2012 between Rosy Senanayake and Kumara Welgama, Sri Lanka's transport minister, as sexist. Welgama is quoted as saying, "You are such a charming woman. I cannot explain my feelings here. But if you meet me outside Parliament, I will describe them … My thoughts are running riot … I don't want to reveal to the public." Senanayake was unimpressed, saying, "......As a woman you are not recognised as a person who has done so many portfolios, but always referred to as the beauty you were in your heyday. I consider that as a sexist remark."
Allegations
Witnesses were appeared before Presidential Commission of Inquiry that Rosy Senanayake had leaked some secret information of the Committee on Public Enterprises in Parliament to the Perpetual Treasuries Limited. Nuwan Salgado, the Chief Dealer of PTL, revealed at the Commission that Arjun Aloysius, the Chief Executive Officer of the PTL, had received a document in 2016 related to the COPE from Rosy's son, the son of Rosy Senanayake. Rosy rejected the allegations stating that she was not a Member of Parliament at the time.
