- isometry
- isomorphic complexes
- isomorphic object
- isomorphic sets
- isomorphy
- isoparametric curve
- isoperimetric
- isoperimetrical inequality
- isopulse system
- isosceles
- isothermal process
- isothermal system
- isotopic
- isotopic medium
- isotopy
- isotopy invariant
- isotropic cone
- isotropic congruence
- isotropic coordinates
- isotropic mapping
- isotropic point
- isotropic process
- isotropic subset
- isotropic subspace
- isotropic subtropic
- isotropic translation
- isotype
- istopy
- item code
- item design
- item name
- item size
- iterated
- iterated extension
- iterated kernel
- iterative division
- iterative process
- iterative search
- iterator
- ITU-T
- ITUM
- iype equivalence
- jabber control
- Jacobian variety
- jam signal
- jamb shaft
- Japanese translation
- JavaScript
- JavaSoft
- JDBC
- jet thrust
- jil crane
- jitter
- job batch
- job entry
- job header
- job step
- joggler
- join endomorphism
- joint development
- joint distribution
- jointer plane
- Josephson junction
- journal article
- joy stick
- joystick configuration
- JPEG
- judgement
- judgement sample
- judgment
- juke-box
- jump
- jump line
- jump operation
- jump phenomenon
- jump table
- jumper
- junction capacitor
- junction point
- justification
- justify inhibit
- juxtapose
- kanji
- kappa
- katakana
- kernel
- kerning
- key assign
- key block
- key click
- key combination
- italic character
- item
- item identifier
- item indexing
- item selection
- itemize
- iterate
- iterated function
- iterated series