The factual entertainment series involves a number of contestants living together - but never actually meeting in person.
Instead, they interact solely via a social media platform called The Circle, competing for a prize given to the most popular contestant.
The contest sees the contestants rate one another and the least liked faces being 'blocked' and removed from The Circle.
In the live final of 2018's first series, catfishing Alex Hobern, who took on the persona of Kate throughout the run, won a total prize of £75,000.
For the second series, which concludes tonight, an even bigger prize of up to £100,000 is to be won.
Ahead of the series 2 final, you can put yourself forward for a potential third series.
To apply for future series of The Circle UK, you must be aged 18 or over at the time of filming (to be confirmed) and be resident or have the right to reside in the UK.
You can register your interest for the application online now at https://www.thecirclecasting.com/.
Currently details about a potential third series have yet to be officially announced.
The second series saw The Circle become more mischievous increasing the gameplay, drama and jeopardy.
Viewers were also be given greater control and increased interactivity with the game. They were able to influence how the contestants play – leading to unexpected and surprising consequences…
Series 2 of The Circle will conclude tonight at 10PM on Channel 4.
You can watch past episodes, including the first full series, online via the All4 Player.