List of junior world records in swimming

The Junior World Records in Swimming are the fastest times ever swum by a "junior" swimmer, with junior defined as the following ages (age as of December 31 of the year of the swim):
 * girls - 18 years old or younger
 * boys - 18 years old or younger

These records are kept/maintained by the FINA (now World Aquatics), and were initially established in March 2014 and based on the meet records from the Junior Worlds meet.

Note: in some cases, there were existing world records (e.g. Katie Ledecky's 400, 800 and 1500 m freestyle, Rūta Meilutytė's 100 m breaststroke) that were not considered for these records (but were faster). Likewise more historical times by juniors were also not considered (e.g. Mary T. Meagher's 2:05.96 in the 200 m butterfly).

Long Course records can be established by breaking the initial time at a meet after April 1, 2014. FINA World Junior Records in 25m pool are recognised starting on January 1, 2015.

Records are recognized for long course (50 m pool) and short course (25 m pool) in the following events: Also recognized are mixed relay records for 4 × 100 medley and free relays.
 * freestyle: 50, 100, 200, 400, 800 and 1500;
 * backstroke: 50, 100 and 200;
 * breaststroke: 50, 100 and 200;
 * butterfly: 50, 100 and 200;
 * Individual medley: 100 (short course only), 200 and 400;
 * relays: 4×50 free (short course only), 4×100 free, 4×200 free, 4×50 medley (short course only) and 4×100 medley.

All records were swum in finals unless noted otherwise.