Couch finished 12th overall in Rio, having successfully progressed through the prelims and semi-finals.
By negotiating the rounds, the 27-year-old kept her impressive record of having reached every global final since 2008.
But this year’s European silver medallist was well down on her best score, collecting 323.70 points in the final.
That was more than 40 points off her international best. She scored 365.90 points to win a World Series silver medal last year in Kazan and also collected 352.70 points to claim silver at this year’s European Championships in London.
But Couch admitted all her focus going into Rio had been on the synchro event with Lois Toulson.
The pair went into that competition with an outside chance of winning a medal, but in the end had to settle for fifth place – the same position she achieved with Sarah Barrow in 2012.
Couch said: “I focused so much on synchro with Lois that going up there without her next to me felt like I was on my own.
“Before the Olympics she was down at my house for a week, I was up with her as well and we just focused so much on the synchro.
“I think I put everything I could into that and didn’t leave enough for my individual so I’m a little bit gutted.”
Couch’s score on Thursday would have been enough for a top eight place in 2008, which is what she achieved as a teenager in Beijing, but her rivals were in top form in Rio.
“I think everybody stepped it up in that final and I just stayed steady,” she said. “I’ve scored over 320 and that used to be my best a couple of years ago but now I’m upset to score that low.
“I know I can do a lot better but I’ve made the final which was my main aim so I have to take something good away from that and I can definitely look back positively on my synchro experience as well.
“I wanted to have fun in that final but it’s just a shame it wasn’t my best performance. I finished with a great dive though so I guess that was good to do.”
Despite her disappointment, Couch, Britain’s most successful platform female diver, has no intention of turning her back on the sport after eight years as one of the world’s best divers.
“It’s been a long run for me and I feel like I’ve been on top of my game for so long now and I’m getting older and it’s getting harder,” said Couch, who was overall World Series champion last year. “But fingers crossed I can keep my body together for the synchro over the next few years.”
Next year’s World Championships will be held in London and most of the British divers are keen to compete in front of a passionate home crowd.
China’s 15-year-old star Qian Ren won the Olympic 10m title with a staggering 439.25 points. Her team-mate Yajie Si was second and Canada’s Meaghan Benfeito was third.
Meanwhile, Tom Daley begins his individual campaign on Friday.
Daley was individual bronze medallist four years ago and has already picked up another medal in Rio, claiming third in the 10m synchro with Plymouth Diving’s Dan Goodfellow.