Dearne and District are the champions of the Central Midlands League after winning their final game 3-0 at AFC Bentley.
The Goldthorpe club are nine points clear of second-placed Doncaster City - who have two games in hand - and have won 27 of 30 league games.
Enzo Guarini, Josh Moore and Tommy Needham netted in front of a crowd of 835.
Dearne are now expected to play in the Northern Counties East League next season.