The 2000 Senior British Open, for sponsor reasons named Senior British Open presented by MasterCard, was a professional golf tournament for players aged 50 and above and the 14th British Senior Open Championship, held from 27 to 30 July at Royal County Down Golf Club in Newcastle, County Down, Northern Ireland, United Kingdom.

[1] Christy O'Connor Jnr beat John Bland by two strokes and successfully defended his Senior British Open title from 1999.

[2][3] The hosting course, one of the oldest on the island of Ireland, originally designed by Old Tom Morris and located in naturally links settings in the Murlough Nature Reserve, stretching along the shores of Dundrum Bay, was established in 1889.

The event was the first of three editions of the Senior British Open held at the Royal County Down Golf Club three years in a row.

The field also included two former runners-up at The Open Championship; Neil Coles (tied 10th) and Brian Huggett (missed the cut).