Ultimately named after Glandore, a village in Co. Cork, but it seems likely that the name "Glandore" was first applied in Belfast to a house on Cavehill Road (BPU, 1894), before being extended to street-names in this neighbourhood. Glandore Avenue, along with Glandore Drive / Gardens / Parade, is part of a group of streets off Antrim Road with names beginning in Glan-. See also Glantrasna Drive, Glanleam Drive, Glantane Drive and Glanworth Drive / Gardens. All of these are place-names in the province of Munster, but beyond this they have little in common. Glan- is usually an anglicisation of the Irish word gleann, 'valley'. However, the Irish name of Glandore is Cuan Dor, in which cuan means 'harbour'.
“That on the application of the owner Mr W. H. McLaughlin four new streets on his property situate off Antrim Road and Skegoneill Avenue be named: ‘Glanworth Street’, ‘Glandore Street’, ‘Glanmore Street’ and ‘Glandore Gardens’.” (21st February 1894).
“That Mr. W. H. McLaughlin of York Road be informed in reply to his application of 9th inst., that the Committee approve of the names ‘Glandore Avenue’, ‘Glanleam Street’, and ‘Glantrasna Street’ for his 3 new streets off Antrim Road and Skegoniel Avenue, but request him to submit another name in lieu of Glandoran Street". (10th October 1894).
“That on the application of the owner Mr. W. H. McLaughlin a new street on his property situate off Glandore Avenue be named ‘Glanna Street’.” (17th October 1894).