Hull were crowned champions with a 3-1 home win to a Wigan side who remain in Sky Bet League One next season.
Grant McCann's men achieved automatic promotion after a 2-1 win over Lincoln last weekend, but needed to better closest rivals Peterborough's result to secure the trophy.
Results elsewhere left both teams happy as City secured a first league title in 55 years, while Latics cannot be relegated.
Hull took the lead after 17 minutes when Keane Lewis-Potter's header was pawed onto the right-hand post by goalkeeper Jamie Jones but squirmed into the back of the net.
Wigan deserved their equaliser two minutes later after Will Keane, given too much space on the left, teed-up Joe Dodoo, who could not miss.
George Honeyman put Hull back in front after 22 minutes when he battered home Mallik Wilks' cute back-heel from the right of the penalty box.
Wigan fought hard to get back into the game after the restart - though the hosts were a constant threat on the counter-attack and improved as the second half progressed.
Hull put the game beyond Wigan's reach after 66 minutes when Wilks stood up a flighted cross from the left and Josh Magennis headed high into the roof of the net.
McCann 'pride' at title win
"I'm very, very proud. I couldn't be more proud of anyone connected with this football club - particularly the fans," said Hull boss Grant McCann. "From the owners and the staff to the players, they've been absolutely magnificent.
"It's been a huge achievement and I'm absolutely delighted It's never about me. This season has been a real collective. The hard work that has gone in from everyone, it's just been incredible and intense. What happened last year (relegation from the Championship), I take full responsibility.
"To turn around the sinking ship to one that floats on top of the ocean, it's been a real team effort from everyone.
"We've had to take bumps in the road on the way and take the hits. But this group have shown a real determination and character to respond every time. Everyone involved needs to enjoy this because it doesn't come around very often.