He served as the Permanent Secretary to the Ministry of Health and Local Government and a member of the Senate of Ceylon.
Kannangara graduated from the University of London with a Bachelor of Arts degree having read English, Latin, Greek, Pure and Applied Mathematics.
He first taught at the Government Training College before sitting for the civil service entrance exam with his friend Paikiasothy Saravanamuttu.
[6] He was a member of the Commission of Inquiry appointed by the Governor General to inquire into Local Government headed by N. K. Choksy, QC.
[9] Kannangara participated the 11th World Scout Jamboree, Marathon Greece 1963 as a Contingent Leader from Ceylon.