The former Shropshire schoolboy is now something of a British comedy institution.
He is known best for his role as Mr Gilbert in The Inbetweeners, as well as starring in Cuckoo and Man Down. And any self-respecting comedy panel game will have booked him at some point.
But despite his hectic schedule, he is very aware of his roots in Shropshire.
Greg visited Thomas Adams School in Wem this week for the first time since he left in the 1980s, taking a personal trip down memory lane and helping to inspire current pupils to fulfil their own potential in the future.
He said: "I'm writing a third series of Man Down now which is why I look tired.
"We've got two more series of TaskMaster, which is a show I do on Dave, and another project that we're hoping to get away – but if I told you, I'd have to kill you."
The comic also hinted at a Christmas project but kept tight-lipped about any further details.
During his visit to the Wem school, Greg handed out signed certificates to 100 former Year 11 students before giving a speech telling stories about his own years. He earlier this year named two of his English teachers, Ed Lamont and Derek Evans, for inspiring him even now.
But the 47-year-old admitted: "This is the first time I've been back. I have in-built fear of authority so I'd have never come back unless I was invited, so this is the first time I could come."
Luckily for Greg, the school did not manage to come up with any embarrassing old pictures of the comic as a pupil.
That might have been just as well. Greg admitted that he had a mischievous streak even then.
One of his funniest memories he recalled at Thomas Adams was similar to a scene in Man Down, pulling the cords of a coat so only the eyes could be seen and unnerving a group of youngsters.
He said: "At lunch times the bright kids had violin lessons and used to go to practice inside in front of this window.
"We used to line up against the window and stare at them until the music teacher would go, 'Get away from here.' Then we used to go back and do it all over again.
"I have so many favourite memories – some of my first times on stage were here."
Greg didn't get into comedy properly until he was 33 after himself embarking on a teaching career. He used this experience to give the pupils advice – learn from his mistakes.
After studying English and drama at Brunel University, the comedy fan had envisaged a career in stand-up but never acted on his instinct.
His father, who had spent his life as a lecturer, said he needed to earn a living and suggested teaching, leading to a 13-year career in the classroom that was only shaken when a girlfriend at the time urged him to "to stop complaining and follow his dream".
Those 13 years' teaching at comprehensives were not wasted, because they provided Davies with no end of material for his stand-up routines and now, Man Down.
He has famously recounted how he was liked by his pupils, but wasn't sure how much they actually learned, recalling recently: "I had one buttock-clenchingly embarrassing moment when the head called me in to tell me one of my pupils had nominated me for the prestigious Teacher of the Year award.
"The pupil had to fill in four pages of documentation, but on the form she had simply written one thing. It said: "Mr Davies is a well good laugh, and he don't make us do no work.
"The head wiped away tears of laughter before throwing the form in the bin."
Greg told pupils at Thomas Adams School: "You haven't got time to mess about doing something you weren't supposed to do.
"It's no bad reflection on teaching, but it it's not the thing you were born to do, don't do it!"
Despite his experience of teaching not being for him, Greg did say that some of his own teachers gave him plenty of inspiration for characters he played, such as the long-suffering Mr Gilbert in The Inbetweeners.
The comic swapped plenty of experiences with staff at Thomas Adams School during his visit this week.
Assistant headteacher Spencer Radford said: "I am delighted Greg accepted my invitation to return to the school where he was educated and give up his time during a very busy schedule.
"He had a tour of the school and spoke fondly of his memories and teachers.
"It is fantastic that our former Year 11 pupils, who achieved great successes in the summer examinations, had the chance to be inspired by him.
"It has widened their horizons for their futures and hopefully they will all go on to be incredibly successful in their own right.
"I look forward to being able to invite some of them back as our special guests in due course."
In honour of the surprise guest speaker for this year's event, the inaugural Greg Davies Performing Arts Awards was also given out.
Rosie Talbot was the recipient, and was described as a focused, reliable and highly professional cast member in all school productions.
Mr Davies handed out certificates including the House Special Award for growing in confidence and communication skills and getting involved in a variety of activities, which went to Callum Hilditch.
The Annie Platt Salver for Mathematics award went to Alanis Anderson; the Gareth Utting English Cup, only the second year it has been presented, was handed to Josh Towers; and Louisa Pickard was named the winner of the David Breeze Salver for Science. All three students showed determination, progression and success in the subjects, the audience was told.
The winner of the Lee Smith Memorial Award for farming and animal care was named as Oliver Whitehead, and Dan Smither and Ellis Hickson were handed the Prefect Salver award.
Beth Ellis, Lauren Fisher, Grace Griffin, Louisa Pickard, Beth Price, Megan Day and Euan Sargant were named Outstanding Academic Achievers as they scored the highest GCSE grades.
Megan Day gained 9 A*s and 2 As while Beth Ellis achieved 8 A*s, 1 A and 1 B, as well as representing England at fencing.
Mr Davies, who until recently was in a long-term relationship with Labour leadership hopeful Liz Kendall, is also patron of Wem Stage Door Youth, which is putting on a production of Annie Jr this week.
Tickets are available for performances on Wednesday at 7.15pm and Saturday at 2.15pm from Jenny Colclough on (01939) 233196.
Greg Davies's top class comedy career:
Greg Davies has become an influential figure on the comedy circuit
He was tonight hosting a Stand Up In Action one-off comedy benefit at Londons Hammersmith Apollo with a host of stars to raise money to aid the refugee crisis
As well as stand-up, he has developed into a comic actor. His Channel 4 sitcom Man Down has just been commissioned for a new series.
The show had featured Rik Mayall and will continue despite the death of the former Young Ones actor
In December, Greg will star in BBC Twos comic drama A Gert Lush Christmas, as Tony, the uncle of Russell Howards character