Students for a Democratic Society (SDS), or New Students for a Democratic Society (New SDS) is a United States student activist organization founded in 2006 in response to the US invasions of Iraq and Afghanistan with the aim to rebuild the student movement. It takes its name and inspiration from the original SDS of 1960–1969, then the largest radical student organization in US history. The contemporary SDS is a distinct youth and student-led organization with chapters across the United States.

Students for a Democratic Society (SDS) was a national student activist organization in the United States during the 1960s and was one of the principal representations of the New Left. Disdaining permanent leaders, hierarchical relationships and parliamentary procedure, the founders conceived of the organization as a broad exercise in "participatory democracy". From its launch in 1960 it grew rapidly in the course of the tumultuous decade with over 300 campus chapters and 30,000 supporters recorded nationwide by its last national convention in 1969. The organization splintered at that convention amidst rivalry between factions seeking to impose national leadership and direction, and disputing "revolutionary" positions on, among other issues, the Vietnam War and Black Power.