The two American actors are delighted to have another investor onboard to build up the Wales-based club.
The Allyn family has purchased a minority stake in the League One team effective immediately.
The billionaire family is wealthy through its family-owned American medical device company Welch Allyn.
A statement from the Welsh side read: "The investment, which was made through Red Dragon Ventures LLC, will help fuel the Club’s lofty ambitions, as well as those of the broader Wrexham community.
"Red Dragon Ventures is a joint venture formed between the Allyn family and Wrexham AFC co-owners Rob McElhenney and Ryan Reynolds focused on driving growth and success in and around Wrexham."
Co-owners Reynolds and McElhenney said: "Wrexham has earned the world’s attention and we are focused on bringing on board world-class partners to help with the next phase of our growth.
"We have been fortunate to get to know the Allyn family and we are blown away by their intelligence, kindness and commitment.
"They are exactly the type of partners we will need for this amazing endeavor."