The 12, which also includes Laura Muir Jemma Reekie, Jake Wightman and Andrew Butchart, form one-sixth of the track and field squad heading to Japan.
Mark Pollard, Scottish Athletics’ head of performance, praised the achievements of athletes to achieve selection in double-figures, but special mention was reserved for Twell and McColgan who are in line to appear at their third Olympics – equalling the tally of Lee McConnell for female athletics representation.
Seven of the team will make their Olympic debuts while it will be a second appearance for Muir, Butchart and marathon runner Callum Hawkins.
Muir will double up in events and enter the 800m as well as the 1500m, while McColgan will also run both the 5km and 10km races. Sprinters Beth Dobbin and Nicole Yeargin will compete in the relay events.
"For athletics in Scotland to have over double figures within a GB and NI team is very rare and reflects the achievement of those picked,” said Pollard. “We regularly look at teams in terms of Scotland’s population ratio and, more often than not, we are punching above our weight and it’s great to see that trend continue.
“It’s also great to see well-known names like Laura Muir, Steph Twell, Eilish McColgan, Callum Hawkins and Andy Butchart returning to the Olympic stage.
“I must mention that for Eilish and Steph this is their third time, which is fantastic achievement and shows tremendous durability and commitment to their sport.
“Equally, we are also pleased for the seven Olympic debutants because that demonstrates the continued growth of athletics in Scotland.
“Hopefully this can inspire the next generation of athletes on our performance pathway to believe in what is possible for Scottish athletes to achieve, should they show similar application and commitment to their sport.”
The seven Scottish Olympic debutants are Nicole Yeargin (4x400m), Steph Davis (Marathon), Jemma Reekie (800m), Beth Dobbin (200m,4x100m), Zoey Clark (4x400m), Josh Kerr (1500m), Jake Wightman (1500m).
They will join a Team GB headlined by the inclusion of 200m world champion and world 100m silver medallist Dina Asher-Smith who will line up alongside Dobbin in the relay as well as the 100m and 200m as she aims for a hat-trick of medals.
World champion Katarina Johnson-Thompson joins the team for her third Olympics and will compete in the heptathlon in the final week of the Games, which begin on July 23 – but the 28-year-old will need to prove her fitness ahead of Tokyo to guarantee her participation. After suffering an achilles injury earlier this year she has been unable to compete in 2021, but last month sources close to the heptathlete claimed she would be ready in time for the Games.
Former American footballer Lawrence Okoye also makes a return nine years after reaching the men’s discus final.
The number of Scottish contenders for this year’s Games was cut during 2021. Middle distance duo, Neil Gourley and Guy Learmonth, both suffered from Covid-19 following outbreaks within British athletes at the European Indoors in early March. Commonwealth medallist Lynsey Sharp announced her pregnancy in May while Eilidh Doyle retired from competition earlier this month.