Isobel Mary Helen Cecilia Joyce (born 25 July 1983) is an Irish former cricketer. She played as a right-handed batter and left-arm medium pace bowler. She appeared in one Test match, 79 One Day Internationals and 55 Twenty20 Internationals for Ireland between 1999 and 2018. She played in her final match for Ireland in November 2018, during the 2018 ICC Women's World Twenty20 tournament. She played domestic cricket for Scorchers, Tasmania and Hobart Hurricanes.