FC United will be playing in the Conference North next season after sealing a fourth promotion in their 10-year history with a 1-0 win over Stourbridge.
The breakaway club were founded as a direct result of the Glazer family's takeover of Manchester United.
The club open their purpose-built stadium next month, when they will play Benfica in a friendly.
Their place in the Evo-Stik Premier League will be taken by Salford City.
Salford - part-owned by former Manchester United players Nicky Butt, Ryan Giggs, Gary Neville, Phil Neville and Paul Scholes - cannot be caught at the top of the First Division North following Darlington's failure to win at Warrington.
FC United secured promotion with a 1-0 win over Stourbridge in front of a crowd of 3,588, courtesy of a header from Greg Daniels.
The victory means next season FC United will play in the same league as Stockport County, who were in League One as recently as 2010.
"The Football League is possible," said FC United manager Karl Marginson. "Most clubs would give anything to have the size of support we have.
"There will be obstacles to overcome, but we have proved to be capable of that over the last 10 years."