Overlap may mean one of:
- In set theory, an overlap of elements shared between sets is called an intersection, as in a Venn diagram.
- In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases
- Overlap (railway signalling), the length of track beyond a stop signal that is proved to be clear of obstructions as a safety margin
- Overlap (road), a place where multiple road numbers overlap
- Overlap add, an efficient convolution method using FFT
- Overlap coefficient, a similarity measure between sets
- Orbital overlap, important concept in quantum mechanics describing a type of orbital interaction that affects bond strength
Overlapping can refer to:
- "Reaching over", term in Schenkerian theory, see Schenkerian analysis#Lines between voices, reaching over