The club was formed in 1876. The club won the prestigious
Sheffield Senior Cup for the first time in 1885–86 when beating
Heeley at
Bramall Lane. The same season the club entered the
FA Cup for the first time, drawing 1–1 with
Staveley F.C. at the neutral Kilnshurst Ground in the first round. However Mexbro' was forced to scratch from the replay as the Sheffield Senior Cup tie with
Owlerton F.C. took precedence and the Sheffield FA refused to grant an extension of time to play the Owlerton tie. The club remained amateur in a professional era, the players – all locals – being paid expenses or "beer money", although many of the team were Methodist teetotallers. In 1891 they were founder members of the
Sheffield & District League. In 1893 they finished as league runners-up, and a year later they went one better, beating
Sheffield Wednesday reserves in the league's play-off final. During the same season they also won the
Sheffield Challenge Cup League. In 1896 they won the
Wharncliffe Charity Cup League, and the following season they entered the
Midland League, finishing 13th in their first season. The 1897–98 campaign was the most successful in the club's history, winning the Midland League title as well as finishing runners-up in the
Yorkshire League and reaching the 5th qualifying round of the
FA Cup (the final stage before the competition proper), where the club lost 1–0 at home, in front of a crowd of 3,500, to
Gainsborough Trinity; the visitors winning thanks to a first-half "flaky" shot, although Boro goalkeeper Hardy later saved a penalty. They decided to revert to more local football in 1899, joining the
Sheffield Association League, but the fans' interest wained and the club seems to have wound up for financial reasons at the conclusion of the 1899–1900 season.
League and cup history • League play-off winners ==Colours==