The Scot clinched her place at Tokyo by winning the European 10,000m Cup in Birmingham on Saturday night in impressive style.
McColgan, who already had the Olympic qualifying time, won the race in 31min 19:21sec after a fast-paced finish while Jess Judd came third behind Israel’s Selamawit Teferi to seal her place in Tokyo in a personal best of 31:20:84.
McColgan said: “The last kilometre was just an absolute blur. I could not ask for any more.
“My mum (Liz) was saying ‘do not leave it to a last lap sprint’ and then I got to 400m and thought ‘oh no, this is a last lap sprint’.”
After competing in the steeplechase at London 2012 and reaching the final of the 5000 metres in Rio 2016, McColgan joins a select band in competing in three Olympics, emulating Lee McConnell and her mother, Liz, who won a silver medal in the 10,000m at Seoul in 1988.
Fellow Scot Steph Twell is likely to join three-Olympic club by competing in the marathon in Tokyo.
Meanwhile, Mo Farah’s Olympic hopes are on the brink after he missed a chance in Birmingham to qualify for next month’s Games.
The 38-year-old was eighth at the British 10,000m Championships and now faces a race against the clock to post the qualifying time ahead of Tokyo.
He finished in 27 minutes 50.54 seconds and will need to go under 27 minutes 28 seconds by June 27 to guarantee a chance to defend his 10,000m titles from 2012 and 2016.
It was a disappointing return to the track for the four-time Olympic champion as he made a comeback for the first time in four years having been focusing on the marathon since 2017.
Farah, who suffered his first 10,000m defeat in a decade, revealed he was battling an injury to his left ankle but insisted it was important to try to qualify in Birmingham.
He said: “I’m disappointed with the result. The last 10 days hasn’t been great but no matter what I achieve in my career it’s important I come out and show at the trials.
“It would have been easy not to show. I dug in deep and with 15 laps to go, you know my face, I was hurting hard. I had to keep fighting and digging in.
“I’ve been carrying a niggle since I came back from training. It is frustrating because I have done a lot of good work in Flagstaff. If you would have asked me two weeks ago it would have been a lot different. It’s part of the sport.
“It just suddenly came on. I have had some treatment to it and then coming back, it really flared up. To be honest, this is the first bit I have done of track in the last two weeks. It is not ideal.
“What makes us great is being able to challenge yourself and prove it. So that is what you have got to do as the next stage.
“I am four-times Olympic champion but that doesn’t mean nothing. You’ve got to go out there each race and mix it with the best.”