Wanderers' triumph, coupled with Manchester City's 2-0 defeat at the hands of Sheffield United, ensured the Trotters moved above Manchester United to claim their first title at this level since 1995.
Two goals from Topi Obadeyi and one from strike partner Kevin Wolze secured the victory with the Magpies' consolation effort coming from David Edgar.
Germany youth international Wolze opened the scoring after 21 minutes when he collected Chris Basham's long ball and smashed his shot home from just inside the Magpies' area.
Wolze then turned provider as he was found by goalkeeper Ali Al-Habsi before firing the ball through to Obadeyi who outpaced the defence and sliding home.
Despite Edgar's close-range header bringing Newcastle back into the game, victory was sealed in the first minute of the second half when Obadeyi scored his second with a well-taken close-range effort.
City needed to avoid defeat to keep alive their hopes of claiming the title, but their dreams ended at Saltergate where two goals from Stephen Quinn completed a 2-0 triumph for the Blades.