McKeown Rattles World Record With #2 Swim In History, O’Callaghan Joins Sub-58 Club In 100 BK


It was no surprise to see the Australian women put on a clinic in the final of the 100 backstroke on Tuesday night at the Olympic Trials, as the world record was nearly broken and the fourth swimmer in history joined the sub-58 club.

Defending Olympic champion and world record holder Kaylee McKeown went out like a bullet, flipping under WR pace in 28.00 before falling off just a touch coming home in 29.41 for a final time of 57.41, the second-fastest in history.

Mollie O’Callaghan, who set a best time of 58.09 in April to become the 7th-fastest performer ever, wasn’t far behind McKeown at the 50 (28.17) and closed strong in 29.71 to hit the touchpad in 57.88 to become just the fourth swimmer in history to break the 58-second barrier.

Split Comparison

McKeown, WR McKeown, AUS Trials O’Callaghan, Old PB O’Callaghan, AUS Trials
28.15 28.00 28.60 28.17
57.33 (29.18) 57.41 (29.41) 58.09 (29.49) 57.88 (29.71)

The 20-year-old joins McKeown, American Regan Smith and Canadian Kylie Masse, who had combined to go 57-something 37 times (33 of them being either McKeown or Smith) before a fourth swimmer joined them.

All-Time Performers, Women’s 100 Backstroke (LCM)

  1. Kaylee McKeown (AUS) – 57.33, 2023
  2. Regan Smith (USA) – 57.51, 2024
  3. Kylie Masse (CAN) – 57.70, 2021
  4. Mollie O’Callaghan (AUS) – 57.88, 2024
  5. Kathleen Baker (USA) – 58.00, 2018

For McKeown, the performance marked a new All Comers Record (fastest on Australian soil), dipping under the 57.45 mark she established at the 2021 Olympic Trials, which was a world record at the time.

All-Time Performances, Women’s 100 Backstroke (LCM)

  1. Kaylee McKeown (AUS) – 57.33, 2023
  2. Kaylee McKeown (AUS) – 57.41, 2024
  3. Kaylee McKeown (AUS) – 57.45, 2021
  4. Kaylee McKeown (AUS) – 57.47, 2021
  5. Kaylee McKeown (AUS) – 57.50, 2023
  6. Regan Smith (USA) – 57.51, 2024
  7. Kaylee McKeown (AUS) – 57.53, 2023
  8. Regan Smith (USA) / Kaylee McKeown – 57.57, 2019 / 2024
  9. Kaylee McKeown (AUS) / Kaylee McKeown (AUS) – 57.63, 2021 / 2023

McKeown, 22, has shown incredible form thus far in Brisbane, with her 100 back swim coming on the heels of a stunning 2:06.63 in the 200 IM on Monday, ranking her #3 all-time.

Showing off the nation’s depth in the event, rising star Iona Anderson was a distant third at the Trials in a time of 58.43, a new lifetime best for the 18-year-old which ties her as the 14th-fastest performer in history.

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11 days ago

Interesting to see she wasn’t actually happy with that swim. I think with her improvement in the 200IM she is possibly in career best form – so was aiming for a WR in the 100BK. Her 50m split (28.00) was perfect, she just faded under the flags. I can’t help but feel that if she didn’t do the 200IM the night before she may have had a tenth or so in her in that last 5 meters. I think she has a 57.1 or 57.2 in her for sure.

11 days ago

Everyone is full of predictions for Mollie.

Let’s hear from the lady herself (last night) for once:

“I’m happy with anything to be honest,” O’Callaghan said of her swim.

“It’s 100 back, it’s a fun event, I don’t really train for it, so to go out there and do a 57 is just amazing.

“I put a lot of pressure on myself regardless whether it’s a main event or not, so I’m really happy with the outcome.”

O’Callaghan is not sure yet whether she will even swim this event in Paris, despite the impressive showing.

“It really depends if I qualify for the next two events [the 200m and 100m freestyle],” O’Callaghan said of the prospect.

Alison England
11 days ago

My guess is that Mollie will not swim the 100 Back, passing the slot to Iona Anderson.

Reply to  Alison England
11 days ago

agree, she won’t risk the 200FR. Shame with the scheduling, but it is rather odd to be world class in 200m free and 100m back.

11 days ago

I think we didn’t see Mollie at the International level with a long pool on her back and considering that Kylie Masse made a mark very similar to her and has a lot of experience, and we still didn’t see the Americans. If he participates, the bronze will be at stake and we don’t know how he would handle it with his main categories there.(I have nothing against her, It is my opinion)

Reply to  gitech
11 days ago


Reply to  ????
11 days ago

They don’t speak English and put this through a translator. That’s why the grammar and pronouns are weird

11 days ago

Regan has her work cut out for her

Reply to  CELL
11 days ago

they all do. this event is a bloodbath.

Alison England
Reply to  Coach
11 days ago

I think Kayleigh will win this. I am a Regan fan. Will see how she does in trials.

Reply to  Alison England
11 days ago

Usually whoever controls the nerves better wins.

11 days ago

We are currently living through the greatest time in history for the women’s 100 backstroke. The amount of talent in this event worldwide is astronomical.

Genevieve Nnaji
Reply to  KSW
11 days ago

The fastest, second fastest, third fastest, and fourth fastest swimmers are all still active.


Aragon Son of Arathorne
11 days ago

Mind bending from MOC. I didn’t think that anyone would challenge Kaylee and Regan this year, but this girl is young and hungry. I want to see her swim butterfly.

Reply to  Aragon Son of Arathorne
11 days ago

she was 58.98 in december where her 100 back was a 59.5 and she hadn’t swam it since december 2021 before that and I don’t think she’s ever really swam it prior to that meet either

Reply to  Aragon Son of Arathorne
11 days ago

It is true that Ocallagahan is exceptional in back and free, which can reveal his vertality and incredible talent

but I don’t think it’s even comparable to douglass, McKeown or mcintosh in terms of versatility,

Last edited 11 days ago by Swimmerfan
Reply to  Swimmerfan
11 days ago

However she, MOC, is the 100 and 200 free (including the WR holder) which are the most competitive & hardest events to win.

Genevieve Nnaji
Reply to  Robbos
11 days ago

The last time 200 free WR holder was also the fourth fastest ever in 100 back was Phelps in 2007.

11 days ago

I’m sure there are other examples, but can someone remind me when the last time an athlete was ranked this highly (or close to it) among all time performers in the 100 BK & 100 FR? Seems like it happens much more often in FL & FR, less so in BK & FR.

Reply to  oxyswim
11 days ago

He’s probably not ranked quite as highly, but kliment kolesnikov comes to mind. 47.1 100 free and 51.8 100 back

Last edited 11 days ago by Towelie
Emily Se-Bom Lee
Reply to  oxyswim
11 days ago

in 2007, coughlin was wr holder in the 100 back and equal second in the 100 free. she may have even achieved it in 2002, 2 years after de bruijn put the wr under 54 and when coughlin’s american record was 53.99. but nuoto’s rankings stop at 53.71, so i can’t be certain

Last edited 11 days ago by Emily Se-Bom Lee
Personal Best
Reply to  oxyswim
11 days ago

I would say Natalie Coughlin between 2004 and 2008 may have come close.

She held the WR in the 100 back up until the 2008 Olympics and after was second to Coventry.

Coughlin also swam a 53.40 in the 100 free semi, which was equaled by Trickett in the final for gold, and the WR was 53.30 by Steffen.

I would imagine for a brief moment in time Coughlin was ranked #1 in the back and #2 in the free. By the time Coughlin set her 100 free PB in 2008, she was no longer #2 ranked (maybe #3) and was also #2 in the 100 back.

Last edited 11 days ago by Personal Best
There's no doubt that he's tightening up
Reply to  oxyswim
11 days ago

After the legendary 4×100 free relay in 2008, Michael Phelps was 3rd all time in the 100 free with 47.51 (behind Sullivan, Bernard) and 4th I think in the 100 back with 53.01 (behind Piersol, Grevers, Stoeckel).

For added context, Phelps’ backstroke time was done in 2007, in textile, when Piersol’s WR was 52.98. Stoeckel and Grevers, aided by the LZR, just dipped under 53 in the 100 back semis earlier the same session as the relay.

Reply to  oxyswim
11 days ago

Popov was a backstroker first

About James Sutherland

James Sutherland

James swam five years at Laurentian University in Sudbury, Ontario, specializing in the 200 free, back and IM. He finished up his collegiate swimming career in 2018, graduating with a bachelor's degree in economics. In 2019 he completed his graduate degree in sports journalism. Prior to going to Laurentian, James swam …

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