39 swimmers from 30 nations. Venue: Olympic Aquatics Centre 東京アクアティクスセンター.
Olympic Qualifyng Time (OQT) - 3:46.78 (13) NOC can enter up to 2 swimmers with OQT.
Olympic Selection Time (OST) - 3:53.58 (26), invitational - A swwimer meeting the "invitation" standard was eligible for entry. But this entry was allotted/filled by ranking.