The ninth series of The Great British Bake Off ™ (The Great British Baking Show ™) began on 28 August 2018, with this being the second series to be broadcast on Channel 4 in the United Kingdom. 

The series was presented by Noel Fielding and Sandi Toksvig, with judges Paul Hollywood and Prue Leith. This series saw a few changes to the usual format: the first episode being Biscuit Week (the previous 8 series began with a Cake Week), the documentary inserts were dropped, and the finale included the competitors doing a technical challenge outside the tent for the first time.

The series was won by Rahul Mandal, with Kim-Joy Hewlett and Ruby Bhogal as the runners-up.