Halloween Halloween (also spelled HalloweŽen) is an annual holiday celebrated on October 31. It has roots in the Celtic pagan festival of Samhain and the Christian holy day of All Saints. It is largely a secular celebration, but some have expressed strong feelings about perceived religious overtones. Irish immigrants carried versions of the tradition to N... more »orth America during Ireland's Great Famine of the 1840s. The day is often associated with orange and black, and is strongly associated with symbols like the jack-oŽ-lantern. Halloween activities include trick-or-treating, wearing costumes and attending costume parties, ghost tours, bonfires, visiting haunted attractions, pranks, reading scary stories, and watching horror films.« less