The 2017–18 Sunfoil 3-Day Cup was a first-class cricket competition that took place in South Africa from 12 October 2017 to 15 April 2018.

[1][2] The competition was played between the thirteen South African provincial teams and Namibia.

The tournament was played in parallel with the 2017–18 CSA Provincial One-Day Challenge, a List A competition which features the same teams.

Northerns and Free State were the defending champions, as the final of the previous tournament ended in a draw.

[7][8] The final was played between KwaZulu-Natal and Namibia at the Kingsmead Cricket Ground in Durban, starting on 12 April 2018.