| jack of all trades, master of none |
| Jane Doe |
| Jedi mind trick |
| Jesus, Mary and Joseph |
| jet-setting |
| jive turkey |
| Joe Public |
| John Citizen |
| Johnny-come-lately |
| join forces |
| jolly along |
| judge, jury and executioner |
| jump at |
| jump down someone's throat |
| jump on |
| jump someone's bones |
| jump the shark |
| junkyard dog |
| just another pretty face |
| just like that |
| jack in |
| jam today |
| Jane Roe |
| jerk off |
| jet set |
| jiak kentang |
| Joe Citizen |
| jog on |
| John Henry |
| John Q. Public |
| join issue |
| jot down |
| juggling act |
| jump at the opportunity |
| jump for joy |
| jump out |
| jump the gun |
| jump to conclusions |
| just about |
| just deserts |
| jabby |
| jack of all trades |
| Jack Tar |
| jam tomorrow |
| Jane Hancock |
| jaw away |
| jerkin the gherkin |
| jerkoff |
| Jesus, Mary, and Joseph |
| jet-setter |
| jewel in the crown |
| jill of all trades |
| Joe Average |
| joe job |
| Joe Random |
| jog someone's memory |
| John Hancock |
| Johnny Appleseed |
| Johnny-one-note |
| joined at the hip |
| join hands |
| join the club |
| jot and tittle |
| judge a book by its cover |
| jug ears |
| juice up |
| jump at the chance |
| jump before one is pushed |
| jumped-up |
| jump in one's skin |
| jump on the bandwagon |
| jump salty |
| jump street |
| jump the queue |
| jump through hoops |
| jungle telegraph |
| jury is out |
| just a minute |
| just a second |
| just folks |
| just the same |