Grenville David "Gren" Alabaster (born 10 December 1933) is a former New Zealand first-class cricketer who played for Otago, Canterbury and Northern Districts. A winner of the New Zealand Cricket Almanack Player of the Year Award in 1972, Alabaster was a right-arm off-break bowler. He toured with New Zealand on occasions, including the tour to Australia in 1973–74, but never in a Test match. His brother Jack Alabaster played 21 Tests.