Involved in Gaelic games administration in County Donegal, McEniff also spent time as Donegal's GAA Central Council delegate. He served on national Gaelic games committees. He has also been a referee. He is Managing Director of the McEniff Hotel Group, which has a presence in such locations as Bundoran, Drumcondra, Sligo, Rosses Point and Westport, County Mayo. Its portfolio includes the Holyrood Hotel (originally bought by his father John in 1951) and the Great Northern Hotel & Golf links (bought from CIÉ in 1977 by Brian and Sean McEniff and Brian's brother-in-law Michael Burke for £125,000). In 1969, McEniff bought the Hamilton Hotel which was next door to the Holyrood Hotel.