Formulas
- Index of coincidence
- Indexed grammar
- Indistinguishability quotient
- Inductive logic programming
- Inquisitive semantics
- Integer-valued function
- Integraph
- Invariant of a binary form
- Inverse-variance weighting
- Inverse Galois problem
- Inversion (discrete mathematics)
- Iodine value
- Ives–Stilwell experiment
- Jacobi's formula
- Jacobi method