Mount Sion (Irish: Cnoc Sion) is a Gaelic Athletic Association club located in Waterford City, County Waterford, Ireland, founded by Brs O'Connor and Malone, teachers in the above school. Although technically separate from the school, the club still maintains a close relationship with the school, sharing the same sports facilities in the city.
The club is mainly concerned with the game of hurling and is the most successful in Waterford with 35 county title wins, although they did win 5 county football titles back in the 1950s. They have also won 2 Munster Senior Hurling titles, in 1981 with victory over Limerick club South Liberties (3-9 to 1-4) and in 2002 beating Sixmilebridge of Clare (0-12 to 0-10). The club has produced a number of All Star winning players for Waterford and also two Inter-county hurlers of the year, Tony Browne in 1998 and Austin Gleeson in 2016. John Keane was also selected on the hurling team of the millennium. Frankie Walsh was the last Waterford man to lift the Liam McCarthy cup in 1959. The club enjoys a rivalry with fellow city club Ballygunner and for much of the 1990s and 2000s the two clubs dominated the county scene in Waterford playing each other in the county final most years. Mount Sion won titles in this period in the years 1994, 1998, 2000, 2002,2003,2004 and 2006 with talented players such a such Ken McGrath, Tony Browne, Brian Greene, Eoin Kelly, & Eoin McGrath. Since 2006, Mount Sion have had something of a quiet period going without a county final win and they came closest in 2014 but Ballygunner came out on top in the county final 2-16 to 0-9.