Born to Abeyratne Banda Ratwatte Basnayake and Thalgahagoda Lewke Punchi née Kumarihamy, he was educated at Trinity College, Kandy.
In 1908 he married Chitravo Katugaha née Kumarihamy,[2] with whom he had ten children including his eldest son, A. C. L. Ratwatte MBE (1909–1971), who also served as the Mayor Kandy (1948), Ceylon's High Commissioner in Ghana (1965) and Ceylon's Ambassador to Malaysia,[3] Stanley Ratwatte and J. C. Ratwatte II.
Cudah Ratwatte served as the Shroff of the Mercantile Bank of Kandy.
On 4 May 1931, Ratwatte was elected unopposed to the 1st State Council of Ceylon, representing Balangoda.
[5] In 1939 he was granted a Knight Bachelor in the New Year Honours list for public services in Ceylon.