Sjostrom and Wiffen end swim worlds with a splash
Elsewhere in the pool in Doha, Isaac Cooper became the first Australian to win the men's 50m backstroke title and Ruta Meilutyte claimed her third straight 50m breaststroke gold.
Sjostrom took her world title tally to 14 in the 50m freestyle, 24 hours after sealing gold in the 50m butterfly and 13 years after she set the ball rolling at the 2009 championships in Rome.
The 30-year-old sent a warning shot across the bows of her younger rivals ahead of the Olympic Games in Paris in five months' time, touching the wall in a time of 23.69, knocking on the door of her own world record.
American Kate Douglass came in second at 23.91 ahead of Katarzyna Wasick of Poland (23.95).
This was Sjostrom's fourth gold in the dash and her third in a row.
"The girls next to me were very fast but I was still able to focus on myself," she said.
"It gives me a lot of confidence coming up to Paris.
"I knew this was going to be a tougher race than the 'fly' yesterday."
Another swimmer putting down a marker for Paris was Wiffen who controlled the 1500m freestyle from start to finish.
He began strongly to open up a large gap and looked on target to trouble the world record of 14mins 31.02sec set by China's Sun Yang at the London 2012 Olympics.
In the end he touched the wall in 14mins 34.07sec, almost 20 metres ahead of second placed German Florian Wellbrock (14:44.61) with France's David Aubry third (14:44.85).
Wiffen was doubling up after claiming the 800m freestyle title on Wednesday.
"I'm so happy to come away with a personal best and two world titles," he commented.
'Little bet'
"I had a little bet with my coach Andy whether I was going to PB or not.
"It's definitely one of my goals to beat the world record sometime. I'm 22 so I've got at least another eight years and another couple of Olympics in me."
Cooper made history for Australia in the 50m backstroke to take gold in 24.13 ahead of 2023 champion Hunter Armstrong, who won his third straight medal in the event in 24.33.
Pole Ksawery Masiuk claimed bronze in 24.44, matching his third from Budapest 2022.
This was Cooper's second medal in Qatar after helping Australia to silver in the mixed medley relay.
Meilutyte put a disappointing performance in the women's 100m breaststroke earlier in the week behind her with a third consecutive 50m breaststroke title.
The 26-year-old from Lithuania, who set a world record of 29.30 on the way to gold in the event last year, held off a charge from the woman who did win gold in the 100 breaststroke, China's Tang Qianting.
Meilutyte timed 29.40, denying Tang by 11-hundredths of a second.
New Zealender Lewis Clareburt claimed 400m medley gold with Briton Freya Colbert winning the women's equivalent.
The United States came out on top in the men's 4x100m medley relay with Australia taking gold for the women in the final event of the championships.