28 swimmers from 23 nations. Venue: Olympic Aquatics Centre 東京アクアティクスセンター.
Olympic Qualifyng Time (OQT) - 4:38.53 (--) NOC can enter up to 2 swimmers with OQT.
Olympic Selection Time (OST) - 4:46.89 (--), invitational - A swwimer meeting the "invitation" standard was eligible for entry. But this entry was allotted/filled by ranking.