Cagdianao got its name from the local amalgam of words “CADA DIA DANAO” meaning peaceful lake until it was coined into Cagdianao.
On the early 19th century, Cagdianao is the southernmost Barangay under the Municipality of Dinagat, until on December 23, 1959, Cagdianao became a municipality by virtue of EO 367 issued by the late President of the Philippines Carlos P. Garcia.
Fourteen (14) barangays compose the Municipality and Barangay Poblacion as its capital
Total population of 16,837 per PSA Survey 2017
Total land area of 22, 704 hectares or 4680.7087 sq. km.