The duo spent the day supporting retail colleagues and welcomed customers betting on the final group stages of Euro 2020.
Grant visited the Paddy Power store based in Headrow, Leeds, while Proctor was based at Kings Cross, London.
During their visits, shop managers informed the executives on Covid-19 safety measures, such as the QR check-in, Perspex screens and hand sanitisers.
The company leaders also spent their time disinfecting all machines and customer touchpoints.
Once the properties were cleaned and the executives educated on protocols, they went behind the tills and served customers in the build-up to the England vs Czech Republic and Scotland vs Croatia games.
Flutter CEO UK & Ireland Grant said: “The ongoing impact of Covid-19 on the retail sector is clear and it’s been a tough year for our colleagues, who have had to adapt to working in an ever-changing environment.
“However, it was great to see our shops and high streets open for business again and to be able to welcome our customers back safely.
“Thank you to everyone at Paddy Power Headrow, Leeds, for showing me the ropes today, it was great to be back behind the counter.”
Flutter UK & Ireland Chairman Proctor added: “I was lucky enough to spend some time with colleagues in our Paddy Power Kings Cross branch today, ahead of another big night for Scotland.
“It’s evident that the reopening of retail and return of live sports has been welcomed by customers and our shop colleagues. We’ve seen steady trade throughout the tournament so far and anticipate that will grow as our home nations proceed through to the knockout stages.
“A massive thank you to all of our retail colleagues for the fantastic job they’re doing to keep our customers safe and entertained.”