LeTou will be the team’s main sponsor as it competes in the multiplayer online battle arena game.
The operator will now have in-game naming rights for the Fnatic Dota 2 team and will provide exclusive content, competitions and social media access.
LeTou CEO Paul Fox said: "LeTou are passionate about our players and partnering with Fnatic gives us the perfect opportunity to engage with their growing esports market.
"Fnatic are known to be the best in the business and we are very excited to work with them to support their Dota 2 team; we will be creating memorable content to bring their community and ours together."
Glen Calvert, Fnatic COO, said: "Both LeTou and Fnatic have had great success in our respective fields, so it is fitting we are now working together to continue that success."
LeTou signed a partnership agreement with Italian Serie A football team Inter Milan last year, having previously sponsored UK football club Swansea City.