Halloween 2026 falls on a Saturday, October 31st, continuing a tradition rooted in the ancient Celtic festival of Samhain, marking the harvest's end and the blurry boundary between living and dead, leading to bonfires, costumes to ward off spirits, and later blended with Christian holidays like All Saints' Day (All Hallows' Eve) and traditions like "souling," eventually evolving into the Americanized, community-focused holiday we know today with trick-or-treating and costumes.