Daniel O'Connor, better known as Danny Boy or Danny Boy O'Connor, is an American rapper, art director, and the executive director of The Outsiders House Museum. O'Connor spent his childhood in New York, before moving to Los Angeles in the 1980s. In the 1990s, O'Connor co-founded the rap group House of Pain, with fellow rapper Erik Schrody (Everlast) and DJ Leor Dimant. Based on their cultural heritage they fashioned themselves as rowdy Irish-American hooligans. O'Connor played the role of art director, designing logos, branding, hype man, and co-rapper. In 1992, with the singles "Jump Around" and "Shamrocks and Shenanigans", their self-titled debut album, also known as Fine Malt Lyrics, went platinum.

House of Pain was an American hip hop trio that released three albums in the 1990s. The group consisted of DJ Lethal, Danny Boy, and Everlast. The group's 1992 hit single "Jump Around" reached number 3 in their native United States of America, number 6 in Ireland and number 8 in the United Kingdom. The group broke up in 1996.