World Records in Swimming

The world records in swimming are ratified by the international governing body of swimming FINA. Records can be set in long course (50 metres) or short course (25 metres) swimming pools. FINA recognises world records in the following events for both men and women.

• Freestyle: 50 m, 100 m, 200 m, 400 m, 800 m, 1500 m
• Backstroke: 50 m, 100 m, 200 m
• Breaststroke: 50 m, 100 m, 200 m
• Butterfly: 50 m, 100 m, 200 m
• Individual medley: 100 m (short course only), 200 m, 400 m
• Relays: 4×100 m freestyle, 4×200 m freestyle, 4×100 m medley

The long course (LCM) records are significantly older than the short course (SCM) records, and are generally viewed as more prestigious of two. LCM records originate as early as the early 1900s (later in the cases of butterfly evolving out of breaststroke). As for SCM, FINA first began the recognition process for these records in March 1991, with the establishment/setting of a standard time in each event (generally tied to the then-known World Best Time (WBT)), which had to be bettered in order for FINA's initially recognized "World Record" in the short course event.

The ratification process is described in FINA Rule SW12, and involves submission of paperwork certifying the accuracy of the timing system and the length of the pool, satisfaction of FINA rules regarding swimwear and a negative doping test by the swimmer(s) involved. Records can be set at intermediate distances in an individual race and for the first leg of a relay race. Records which have not yet been fully ratified are marked with a '#' symbol in these lists.

Most of the records below were established by swimmers wearing bodysuits or suits made of polyurethane or other non-textile materials allowed in the race pool from February 2008 until December 2009. On the eve of the 2009 FINA World Championships in Rome, the international governing body for five Olympic aquatic sports voted to ban the use of bodysuits and all suits made of non-textile materials starting 1 January 2010. The suits seemed to improve the performance in those with larger physiques, boosting performance in some athletes more than others, depending on morphology and physiology, and creating an angle of buoyancy that was improved in some more than on others..