Gregory Anthony Halman (August 26, 1987 – November 21, 2011) was a Dutch professional baseball outfielder. He played with the Seattle Mariners of Major League Baseball (MLB) during the 2010 and 2011 seasons. He also played internationally with the Dutch national team in the 2009 World Baseball Classic. He died of stab wounds in Rotterdam after the 2011 MLB season. His brother was arrested in connection with the stabbing but was acquitted on the grounds of temporary insanity.