Glentoran Football Club is a professional football club that plays in the NIFL Premiership. The club was founded in 1882 and plays its home games at The Oval in East Belfast. Club colours are red, green and black. Their main rival is Linfield with whom they contest the Big Two derby and who collectively are known as the "Big Two", as they have traditionally dominated local football in Northern Ireland since the demise of Belfast Celtic. The two play a league match on Boxing Day each year, which regularly attracts the largest attendance of the Northern Irish League season.
The team has won the top flight of Irish football 23 times, placing second in league titles behind Linfield. However, the last time they achieved this success was the 2008–2009 season. They have also won the Northern Irish Cup 23 times, the Northern Irish League Cup 7 times and the County Antrim Shield 27 times. One of the Shield wins, in 1908-09, was achieved by Glentoran IIs.