Spencer Pratt (born August 14, 1983) is an American reality television personality who rose to fame in 2007 after joining MTV's The Hills, where his relationship with Heidi Montag and a bitter feud with co-star Lauren Conrad became the show's central drama. After marrying Montag in April 2009, the couple made controversial appearances on I'm a Celebrity...Get Me Out of Here! and two seasons of the UK's Celebrity Big Brother (2013 and 2017), later starring in the reboot The Hills: New Beginnings and running a crystal business.

In 2013, he completed a political science degree from USC, and in 2026 he published a memoir titled The Guy You Loved to Hate: Confessions from a Reality TV Villain. His life took a dramatic turn when his Pacific Palisades home was destroyed in the January 2025 Palisades Fire, prompting him to sue the city of Los Angeles and publicly criticize Governor Gavin Newsom and Mayor Karen Bass. Capitalizing on his newfound political profile, Pratt announced his candidacy for mayor of Los Angeles on the fire's one-year anniversary, but he finished third in the 2026 primary and failed to advance to the general election. From reality TV antagonist to political hopeful, Pratt's career showcases a remarkable reinvention—blending celebrity culture, business ventures, and public service ambitions.