The British swimming champions over 400 metres freestyle, formerly the (Amateur Swimming Association (ASA) National Championships) are listed below.
[1][2] The event was originally contested over 440 yards and then switched to the metric conversion of 400 metres in 1971.
The most successful male and female competitors in the history of the event are Paul Palmer with six titles, and Liz Long and Sarah Hardcastle with five titles each.
Palmer, Long, Brian Brinkley and James Guy share the record for consecutive titles at four.
The current champions (2024) are Kieran Bird and Holly Hibbott (their first in both cases).