Isaac Boss (born 9 April 1980, in Tokoroa, New Zealand) is a New Zealand–born Irish rugby union footballer.
His grandmother was born in Glenarm, County Antrim, thereby qualifying him to play for Ireland.He plays scrum-half or fullback and has played for Leinster, Ulster and the Ireland national team.
He weighs 88 kg and is 1.78 m tall.
He is the only player to play over 100 games for two different irish provinces.