In the 1997 post season, Sullivan was selected to play for Great Britain on the wing in the first match of the Super League Test series against Australia.
Sullivan played for St. Helens on the wing in their 1999 Super League Grand Final victory over Bradford Bulls.
As Super League V champions, St. Helens played against 2000 NRL Premiers, Brisbane Broncos in the 2001 World Club Challenge.
Anthony Sullivan played left wing in St. Helens' 24–14 victory over Rochdale Hornets in the 1991–92 Lancashire Cup Final during the 1991–92 season at Wilderspool Stadium, Warrington, on Sunday 20 October 1991, and played left wing in the 4–5 defeat by Wigan in the 1992–93 Lancashire Cup Final during the 1992–93 season at Knowsley Road, St. Helens, on Sunday 18 October 1992.
[7] Anthony Sullivan played left wing in St. Helens' 16–25 defeat by Wigan in the 1995–96 Regal Trophy Final during the 1995–96 at Alfred McAlpine Stadium, Huddersfield on Saturday 13 January 1996.