Series Four of Ninja Warrior UK, a British physical obstacle assault course game show, began airing on 14 April 2018.
Unlike previous series, it was announced on 28 August 2017 that the competition would feature a selection of celebrity contestants, including Gethin Jones, Harry Judd, Jenni Falconer and Marvin Humes.
The most common featured included Jump Hang - this series saw a few new variations on the obstacle - Floating Steps, and Log Runner - this obstacle was new for this series.
This series saw the introduction of new obstacles used on the course - Rope Climb, Floating Steps, Tick Tock and Bar Hop For the semi-finals of this series, the semi-finalists had to complete Stage 1 of the course within three minutes.
Alongside the Floating Steps and Warped Wall, they also had to contend with Ring Swing, Broken Bridge, Bar Hop, and Wind Chimes.