The 1998 Senior British Open was a professional golf tournament for players aged 50 and above and the 12th British Senior Open Championship, held from 6 to 9 August at Royal Portrush Golf Club in Portrush, County Antrim, Northern Ireland, United Kingdom. In 2018, the tournament was, as all Senior British Open Championships played 1987–2002, retroactively recognized as a senior major golf championship and a PGA Tour Champions (at the time named the Senior PGA Tour) event.