Night one of the U.S. Olympic Team Trials – Swimming presented by Lilly kicked off with Katie Ledecky (Bethesda, Md./Gator Swim Club) and Aaron Shackell (Carmel, Ind./Carmel Swim Club) winning the 400m freestyle events. Gretchen Walsh (Nashville, Tenn./University of Virginia) earned the top spot for tomorrow’s final in the 100m butterfly, setting a world record with a time of 55.18.

USA Swimming made waves in the world of aquatic sports by setting a new benchmark for the largest swim meet ever. With an unprecedented 20,689 attendees on night one, this historic event has firmly cemented its place in swimming history.

Women’s 100m Butterfly – Semifinal

1 – Gretchen Walsh (Nashville, Tenn./University of Virginia), 55.18*

2 – Torri Huske (Arlington, Va./Arlington Aquatic Club), 55.79

3 – Regan Smith (Lakeville, Minn./Longhorn Aquatics), 55.92

*World Record

Men’s 400m Freestyle – FINAL

1 – Aaron Shackell (Carmel, Ind./Carmel Swim Club), 3:45.46

2 – Kieran Smith (Ridgefield, Conn./Ridgefield Aquatic Club), 3:45.76

3 – David Johnston (Dallas, Texas/The Swim Team), 3:46.19

Shackell on making his first Olympic Team: “I think it's just a moment I've always dreamed of. Watching previous Olympic Trials, or really any sport, getting a medal in front of a massive crowd is something I've always dreamed of. Then raising my hands and everyone cheering, that's a moment that every kid dreams about.”

Women’s 400m Freestyle – FINAL

1 – Katie Ledecky (Bethesda, Md./Gator Swim Club), 3:58.35

2 – Paige Madden (Mobile, Ala./New York Athletic Club), 4:02.08

3 – Jillian Cox (Vineland, N.J./Team Charlotte Swimming), 4:06.89

Ledecky on making her fourth Olympic Team: “It's special. I remember three years ago just trying to process being a three-time Olympian, and now being a four, I just tried to enjoy each moment tonight. It was pretty exciting this morning just to feel the atmosphere, kind of get those first race jitters out of the way.”

Men’s 100m Breaststroke – Semifinal

1 – Charlie Swanson (Richmond, Va./NOVA of Virginia), 59.34

2 – Josh Matheny (Pittsburgh, Pa./Indiana Swim Club), 59.42

3 – Nic Fink (Morristown, N.J./New York Athletic Club), 59.46

Competition continues through Sunday, June 23 at Lucas Oil Stadium. Tomorrow’s finals feature the men’s 400m IM final, women’s 100m butterfly final, 200m freestyle semifinal, women’s 100m breaststroke semifinal, men’s 100m backstroke semifinal, men’s 200m breaststroke final, and the women’s 200m freestyle semifinal. Prelims will begin at 11 a.m. ET, while finals start at 8 p.m. ET. Meet information and the complete competition schedule can be found here.

Click here to see the full broadcast schedule for the 2024 U.S. Olympic Team Trials – Swimming presented by Lilly. Live streams of all prelims sessions are available on the USA Swimming Network. Live results will be posted to @USASwimmingNews on X.