- Joyful
- Joystick
- Jubilation
- Judas
- Judas iscariot
- Judged
- Judgement
- Jug
- Jugged hare
- Jugular
- Jujitsu
- Jujuba tree
- Jump at
- Jump on
- Jump-lead
- Jumped-up
- Jumping
- Jumping locust
- Jumping-off point
- Juncture
- June
- Junk bond
- Junk food
- Jurassic
- Just about
- Just as the doctor ordered
- Justifiable homicide
- Justly
- Justness
- Juvenile delinquency
- Juvenilia
- Jujube
- Jab in
- Jabbering
- Jack timber
- Jack tree
- Jackboot
- Jacket
- Jackfruit
- Jacks
- Jag
- Jailbreak
- Jamb
- Janaka
- January
- Janus-faced
- Japan
- Jasmine flower
- Jasmine plant
- Jaundice
- Jauntily
- Jauntiness
- Jaunty
- Java
- Jaw dropping
- Jcb
- Jcc
- Jealousy
- Jean
- Jeep
- Jehovah
- Jellied
- Jeopardise
- Jeopardize
- Jerry-building
- Jerry-built
- Jersey
- Jerusalem
- Jesus
- Jet black
- Jeweler
- Jewelled
- Jeweller
- Jewellery
- Jewelry
- Jewish colony
- Jib
- Jibber
- Jiffy bag
- Jig is up
- Jihad
- Jingling ornament for the leg
- Job batch
- Job creation
- Job satisfaction
- Job sharing
- Job title
- Jocundity
- Jog trot
- Joggle
- John bull
- Johnny-come-lately
- Join
- Join forces with
- Jointly
- Joke
- Joking
- Jolliness
- Jonesia asoca
- Josh