Deshamanya Kanapathipillai William "Bill" Devanayagam (26 March 1910 – 17 December 2002) was a Sri Lankan Tamil lawyer, politician, government minister and Member of Parliament.

[1] A Roman Catholic, Devanayagam was educated at St. Joseph's College, Colombo.

[2][3] A keen sportsman, he captained the school's cricket team in 1930 and was the East Ceylon champion in tennis.

[2][3] After school, Devanayagam joined Ceylon Law College, qualifying as a proctor.

[2][3] Devanayagam contested as an independent candidate from Kalkudah at the 1947 parliamentary election but was defeated by V.