The headline
The largest US public school districts by number of schools operated are extraordinary administrative entities. The Puerto Rico Department of Education runs 861 schools as a single district. Los Angeles Unified runs 785. Chicago Public Schools runs 644. Miami-Dade County, Clark County (Las Vegas), Broward County, Hillsborough County, the Hawaii state district, and Orange County (FL) each operate more than 280 schools.
Why size matters
Large districts have economies of scale that smaller districts lack: dedicated curriculum offices, transportation logistics, in-house teacher training, capital project teams. They also have governance challenges that smaller districts avoid: a single school board overseeing operations for half a million students, principal evaluation systems that must work consistently across hundreds of buildings, and the political complexity of school-closure or boundary decisions that affect tens of thousands of families simultaneously.
The state-by-state version
Within most states, one or two districts operate a disproportionate share of the state's public schools. In Hawaii (296 schools), it's literally the entire state. In Florida, the seven largest county districts (Miami-Dade, Broward, Hillsborough, Orange, Palm Beach, Duval, Pinellas) operate roughly half of the state's schools combined. In Maryland, the four largest districts (Montgomery, Prince George's, Baltimore County, Anne Arundel) operate about a third.
Why district size matters
For families and policymakers, district size is a relevant variable in everything from school-choice politics to teacher-contract negotiation to capital-improvement planning. The dynamics of LA Unified are not the dynamics of a 5-school rural district, and treating them as equivalent units of analysis distorts most education policy debates.
Methodology
Source: NCES Common Core of Data 2024-25 school universe file, aggregated by reported district name + state. Districts are counted by the number of schools currently operating under their administration, not by enrollment. Charter authorizers that operate as district equivalents are included when so reported by the state to NCES.