F
- Fane River, County Louth
- Farset*
- Faughan
- Feale
- Fergus
- River Ferta, County Kerry
- Fettercairn Stream, County Dublin
- Fiddaun River, County Mayo
- Figile River, County Kildare
- Finglas River, County Dublin
- Finglaswood Stream, County Dublin
- Finn*
- Finned River, County Sligo
- Flurry River, County Louth*
- Forrest Little Stream, County Dublin
- Foyle — that portion named "Foyle" forms the Republic of Ireland-Northern Ireland border*
- Fox Stream, County Dublin
- Foxrock Stream, County Dublin
- Fury*
- Furry Glen Stream, County Dublin
Read more about this topic: Rivers Of Northern Ireland