He served as the Sri Lankan Cabinet Minister of Labour, Housing, Social Services, Finance, Commerce, Food, Trade and Shipping and in other government positions in a career spanning three decades.

[2] As a writer, Ilangaratne is best known for writing the popular Sinhala-language children's novel Amba Yaluwo (1957).

He began attending school in 1917 at Galagedera Vidyalaya [4] and received his secondary education from St. Anthony's College, Kandy.

He soon had to step down due to an election petition that striped him of his civic rights and in the by-election that followed, his wife Tamara Ilangaratne contested and won the Kandy electorate in June 1949.

Joining S. W. R. D. Bandaranaike in his newly formed Sri Lanka Freedom Party, Ilangaratne contested the 1956 general election from Galaha and re-entered to the House of Representatives in the landslide victory the Sri Lanka Freedom Party gained defeating Theodore Braybrooke Panabokke.

He lost his seat in the 1965 general election losing to M. A. Daniel from the United National Party.

Since then, he made the plays Manthari Hamuduruwo, Nataka Ata, Mokada Mudalali and Nikan Awa.

After the failure in politics in 1948, he was later introduced to film producer K. Gunaratnam by his friend lawyer S. Nadesan.

Critics pointed out that Ilangaratne's innovative acting is due to the politics and satirical dialogue that accompanies the success of the film.