The song is listed as "traditional" in the book "The Gold Sun of Irish Freedom" by Danny Doyle and Terence Folan (1998).

"Rapparee" is derived from the Irish "rapaire" meaning a short rapier or pike, their favoured weapon. Originally, they were the displaced Catholic natives who became outlaws and preyed on their British conquerors. The term came into vogue around 1690, prior to that these rebels were called "kerne" (Ir.- ceitearn -"trooper") and "tories" (Ir. - toraidhe - "raider"). In England "tory" was applied with derision to the Jacobites and gradually evolved in an alternative name for what became the Conservative Party. The best known rapparee was Redmond O'Hanlon (1640-81) but the greatest seems to have been Dudley Costello (c1620-67) in Mayo and Ned of the Hill (Edmund Ryan,1670-1724) in Tipperary.

Anything definitive on authorship of the song?