The Coomsaharn char (Salvelinus fimbriatus; the spellings Coomasaharn and charr are also used; Irish: ruabhreac Chom Sathairn) is a species of lacustrine char fish in the family Salmonidae.

[4][5] The English word "char[r]" is thought to derive from Old Irish ceara/cera meaning "[blood] red",[6] referring to its pink-red underside.

[9] Lough Coomsaharn (/ˌkuːməˈsæhərən/) derives its name from the Irish Com Sathairn, "hollow of Saturday(?)".

It is distinguished from other Salvelinus in Ireland by large eyes,[11] having 27–30 gill rakers, with 16–20 on the lower part (hence the species name fimbriatus, "fringed").

[13] The Coomsaharn char are a remnant fish of the Last Ice Age.