Chiasm may refer to:
- Chiasm (musical project), an electronic music project by Emileigh Rohn
- Optic chiasm, the part of the brain where the optic nerves partially cross
- Chiasma (genetics), the point where two chromatids are intertwined (interwoven) in a cell
- A tendinous chiasm, the spot where two tendons cross. The tendon of the flexor digitorum longus muscle forms two: the crural chiasm (with the tendon of the tibialis posterior muscle) and the plantar chiasm (with the tendon of the flexor hallucis longus muscle).