Derry Girls was created and written by Lisa McGee and was inspired by her own experiences growing up in an Irish Catholic family in Derry during the final years of the Troubles in the 1990s.

The fictional school Our Lady Immaculate College is based on the real-life Thornhill College, which McGee herself attended.

The character James was based on the idea of a boy attending an all-girls Catholic school for safety, and much of the show's humor mixes fictional teenage plotlines with real historical events like the 1994 IRA ceasefire, Bill and Hillary Clinton's 1995 visit, and the 1998 Good Friday referendum.

A storyline involving Erin writing a letter to Chelsea Clinton was based on a real event from Lisa McGee's own life.

Filming took place in Northern Ireland, mostly on location in Derry and Belfast; the first series was filmed from May to July 2017.

Train scenes in series 3 episode 3 were shot at the Downpatrick and County Down Railway, while the episode's ending was filmed at the recently-closed Barry's Amusements in Portrush.

Production of the third series was delayed by the COVID-19 lockdown after being due to start in spring 2020, eventually resuming filming in late 2021.

The first series became the most-watched series in Northern Ireland since modern television records began in 2002, drawing an average audience of 519,000 and a 64.2% audience share.

Derry Girls became Channel 4's most successful comedy since Father Ted and was renewed for a second series just one day after the pilot episode aired.

A 2022 episode of The Simpsons featured an ice cream parlour called 'Dairy Girls Ice Cream,' which writer Matt Selman confirmed on Twitter was a deliberate reference to Derry Girls.

The show inspired a mural of its main cast painted on the side of Badgers Bar and Restaurant at 18 Orchard Street in Derry, which became a popular tourist attraction.

The main cast appeared together in a 2018 charity special of The Crystal Maze for Stand Up to Cancer UK, and several cast members later competed in a 2020 New Year's special of The Great British Bake Off, which Saoirse-Monica Jackson won.