1890 Ulster Senior Football Championship

The 1890 Ulster Senior Football Championship was the second staging of that competition and was contested by three counties; Armagh, Antrim and Tyrone.

Tyrone (represented by Owen Roe O'Neill's Cookstown) received a bye into the final, whilst Antrim (represented by Armagh Harps) and Antrim (represented by Belfast) competed in a semi-final.

The defending champions, Monaghan, did not enter. Armagh won the competition, claiming their first Ulster Championship.