The show, which will air on Disney Plus, will follow the two actors buying the fifth division Welsh football club to try and improve the team's fortunes.
In the trailer, fans are seen asking questions of the duo's motives for wanting to buy the club with Reynolds using some of his trademark humour to win them over. Watch it below.
A synopsis for the documentary reads: "Ryan Reynolds (Deadpool) and Rob McElhenney (It’s Always Sunny in Philadelphia) bought the third-oldest professional football club in the world. It is a Welsh team in the town Wrexham and the team is currently on the brink of dissolution.
Welcome to Wrexham is a docuseries tracking the dreams and worries of Wrexham, a working-class town in North Wales, UK, as two Hollywood stars take ownership of the town’s historic yet struggling football club."
The series also promises to take fans "inside the sport" as never before and will feature the two actors as they try and get to grips with all aspects of running a football club.
Since 2011, Wrexham had been owned by a trust of fans after the club went into administration after being relegated out of the Football League in 2008.
The trust agreed to sell the club to the two Hollywood actors to help ensure its financial future with the transfer of ownership being completed February 2021.
Due to the Covid-19 pandemic, Reynolds and McElhenney had to wait until October to attend a game. They would later attend Wrexham's FA Trophy final at Wembley along with Will Ferrell.
Reynolds and McElhenney had never worked together or had any involvement in professional football prior to purchasing Wrexham.
Welcome to Wrexham starts streaming on Disney Plus from 25 August.
Watch below: Ryan Reynolds' Wrexham AFC purchase boosts interest in club's sponsor.