Lambda Chi Alpha (ΛΧΑ), commonly known as Lambda, is a college fraternity in North America. It was founded at Boston University in 1909. Lambda Chi Alpha is one of the largest social fraternities in North America with over 300,000 lifetime members and active chapters and colonies at 195 universities. The youngest of the 15 largest social fraternities, Lambda Chi Alpha has initiated the third-highest number of men among all fraternities, based on NIC statistics. Lambda Chi's international headquarters is located in Carmel, Indiana, outside Indianapolis. Its members are referred to as Lambda Chis, LXAs, LCAs, Lambdas, Chops, and Choppers. Lambda Chi Alpha is a member of the North American Interfraternity Conference (NIC). Lambda Chi Alpha briefly left the conference in October 2015 before rejoining in November 2023.