The Ponds Forge competition was acting as the Olympic trials for the Great Britain team.
By winning the event and scoring an impressive 347.90 points in the final and 320.80 points in the prelim, Barrow has met all the criteria to earn selection for Rio.
The pressure was on the city diver to perform in Sheffield after losing her GB synchro spot to Leeds teenager Lois Toulson.
However, she handled the pressure brilliantly to prove a point to national performance director Alexei Evangulov, who had not selected her for the European Championships, despite her finishing second to Plymouth team-mate Tonia Couch at the National Cup in January.
Barrow finished more than 24 points ahead of second-placed Georgia Ward in Sheffield.
London diver Ward had controversially been selected ahead of Barrow for last month’s European Championships.
Barrow opened the final with an great dive which scored her 76.80 points and she never looked back, scoring 72.00, 64.40, 67.50 and 67.20 for her other efforts.
“I’m really happy with that result,” said Barrow. “It’s been a tough time coming back from injuries. Having two years of injuries and having to stop and start with my diving was tough.
“But this time I felt like I came back properly and I spent some time up in Leeds with the physios and worked really hard to come to this result.
“I’ve worked really hard to make sure I was where I needed to be. I stuck at my diving. I have a good mindset and I feel like that showed today.”
Couch, who is expected to fill one of Britain’s two individual spots in Rio, did not take part Saturday’s individual final after winning the synchro event the day before with Toulson.
Fellow Plymouth divers Shanice Lobb, Victoria Vincent and Robyn Birch, however, did compete.
Lobb was fourth with 280.30 points, Vincent was fifth with 252.20 and Birch seventh with 232.90.