Run-off or runoff may refer to:

  • Surface runoff, the flow of water, from rain, snow melt, or other sources, over land
    • Runoff model (reservoir), a mathematical model describing the rainfall-runoff relations of a rainfall catchment area or watershed
    • Runoff curve number, an empirical parameter used in hydrology
  • Runoff voting or Two-round system, a voting system used to elect a single winner, whereby only two candidates from the first round continue to the second round
  • Instant-runoff voting, an electoral system in which voters rank the candidates in order of preference
  • RUNOFF, the first computer text formatting program, running on the CTSS operating system
  • Runoff (program), the type-setting program on the Multics operating system
  • Run-off area, an area on a racetrack for racer safety
  • Bleed (printing), printing that goes beyond the edge of the sheet after trimming