The 2017–18 FAW Welsh Cup was the 131st season of the annual knockout tournament for competitive football teams in Wales.

[1] The winners Connah's Quay Nomads qualified for the 2018–19 UEFA Europa League preliminary round.

[4] Treharris Athletic Western were disqualified for fielding an ineligible player and Llanrumney United replaced them.

North West region Glantraeth FC were due to play Prestatyn Sports but withdrew.

[7] Results:[1] The draw for the fourth round was held on 4 December 2017.