The 2019 Australian Swimming Championships were held from 7 to 12 April 2019 at the South Australia Aquatic and Leisure Centre in Adelaide, South Australia. Following Australia's performance at the 2016 Rio Olympics where 29 medals were won and finishing 10th on the medal tally, Swimming Australia announced in the February 2017 that the timing of the selection trails would be modified. Historically, the trails were held in April several months before the Olympics were held. This will be now changed to follow the American model where the trails are held six weeks before. The 2019 Australian World Swimming Trails will be held at the Brisbane Aquatics Centre in June 2019 and will be selection trails for the 2019 World Aquatics Championships in Gwangju, South Korea. This event doubled up as the national trials for the 2019 World Para Swimming Championships in London, the 2019 Summer Universiade in Naples, Italy and the 2019 FINA World Junior Swimming Championships in Budapest, Hungary. There was an increase in the number of events contested from 63 to 64 from the with addition of the mixed 4 × 100 m medley relay. This was due to the IOC announcing in June 2017 that this event as well as the men's 800 m freestyle and the women's 1500 m freestyle events will be added to the Olympic swimming program at the Tokyo 2020 Games. Emily Seebohm chose to miss this meet to participate in the inaugural FINA Champions Swim Series event in Guangzhou, China, while Thomas Fraser-Holmes was away competing at the Helsinki Swim Meet and Bergen Swim Festival. Mack Horton was forced out due to a shoulder injury. During night three of the championships, Cate Campbell on behalf of Swimming Australia paid tribute to Kenneth To who died a few weeks prior. Defending women's 200 metre backstroke champion Kaylee McKeown was disqualified during the heats of the event. She was permitted to swim a time trail where she stopped the clock at 2:08.56 well ahead of Minna Atherton's winning time of 2:11.18 in the final. The legends relay was a mixed 4 × 50 m freestyle event swam on the penultimate night of the meet. The team were:
* Team Bramham - , Brooke Hanson, Sam Bramham and Robert van der Zant
* Team Klim - Michael Klim, Dimity Douglas, Sally Hunter, Phil Rogers
* Team Trickett - Christian Sprenger, Linley Frame, Libby Trickett, Bill Kirby
* Team Schipper - Brenton Rickard, Anna McVann, Jessicah Schipper, Craig Stevens The event was won by Team Bramham in a time of 1:47.14, followed by Team Schipper (1:49.72), Team Trickett (1:50.01) and Team Klim (1:52.54).