Ryan Reynolds is doubling down on his investment in the sports world, and it's in large part due to fans of his 2 biggest franchises ... TMZ has learned.

The actor's investment firm, Maximum Effort, announced Thursday it's spending big to become one of the leading investors in Homage, a sports apparel company with a specialty in vintage-style getups.

Sources with direct knowledge tell us ... RR is thrilled about the new addition to his portfolio because of his experiences with his English soccer club and the 'Deadpool' movies.

In fact, we're told Ryan was inspired to link up with Homage after seeing how fans love repping gear for Deadpool and Wrexham A.F.C. Our sources tell us ... the action movie star sees a lot of opportunity in sports apparel, not just business-wise ... but also creatively, and he intends to be a hands-on partner.

Homage has had several successful partnerships, creating vintage-styled merch for the NBA, NFL, the WNBA, Major League Baseball and WWE. And now, with Ryan's company's investing, Homage can expand production.

While Ryan is best known for acting, he's actually become quite the business titan. In fact, he's reportedly set to make about $300 million from T-Mobile's recent acquisition of Mint Mobile ... another small company he'd invested in before the T-Mobile swooped in.

He's also added Aviation Gin, Fubo, Club Necaxa, and Alpine’s Formula 1 team to his already impressive roster of investments.

RR's fans will, no doubt, be clamoring for special edition 'Deadpool' or Wrexham merch, and here's the good news ... it's possible!