Georgia Davies and Molly Renshaw broke British records at the ASA's winter meet in Sheffield.
Commonwealth champion Davies knocked one tenth of a second off her previous best to take gold in the 50m backstroke in a time of 26.24 seconds.
Renshaw won the 100m breaststroke with a British record time of 1:05.22.
Davies and Renshaw then joined Loughborough team-mates Rachael Kelly and Sophie Smith to win the 4x100m medley relay title.
Welsh record holder Jemma Lowe won the 100m butterfly, while Joe Elwood added the men's 100m backstroke title to the gold he won over 50m on Friday.
Elwood, who won in lifetime best 52.22 seconds, said: "My legs became really heavy in the second half and my arms had to work really hard to keep them from sinking.
"I definitely wasn't expecting two golds and given how tough that was, I am absolutely delighted."
City of Manchester's Sam Horrocks took the 200m butterfly title and Lawrence Palmer won 50m breaststroke gold.