It's a Sin features a main cast consisting of Olly Alexander, Omari Douglas, Callum Scott Howells, Lydia West, and Nathaniel Curtis.

Other actors cast were David Carlyle, Keeley Hawes, Shaun Dooley, Tracy-Ann Oberman, Neil Patrick Harris and Stephen Fry.

The series was directed by Peter Hoar, produced by Red Production Company, and premiered in the United Kingdom on Channel 4 on 22 January 2021.

Despite its London setting, It's a Sin was filmed mainly in Manchester, with other locations used in Liverpool, Bolton, Eccles, Bangor, and Rhos-on-Sea.

Ash is irritated after his job is forced to abide by new rules forbidding public institutions from informing children about homosexuality under Section 28.

Roscoe takes a personal stand against Prime Minister Margaret Thatcher after Arthur abruptly ends their relationship.

Davies' plans to write a series depicting gay life during the 1980s and the UK AIDS crisis were based on his own and his friends' experiences, and to commemorate the generation who died from the illness.

[21] Davies developed the series with Nicola Shindler, who served as Executive Producer and had the assistance of her Red Production Company.

[28] Welsh actor Callum Scott Howells was cast in his first television role playing Colin Morris-Jones, a gay man from Wales.

[35] Other castings included Andria Doherty as Eileen Morris-Jones and Tracy-Ann Oberman as Carol Carter, an acting agent who signs up Ritchie.

This casting was intentional; Davies stated "for my one programme, for these five hours, I wanted to create a safe space where gay actors could voluntarily come in and be themselves.

"[44] It's a Sin is set in 1980s England and to reflect the times a series of period props were introduced to outdoor filming locations.

[44] Additional filming then took place at a shopping centre in Eccles, a residential street in Heaton Moor and Le Mans Crescent in Bolton.

The release, used to promote the series was also used to raise money for the George House Trust, a charity supporting those living with HIV.

The first episode was watched live by 1.6 million viewers on Channel 4, a benchmark for a drama launch previously hit a year earlier by Deadwater Fell.

[67] Official ratings are taken from BARB, utilising the four-screen dashboard which includes viewers who watched the programme on laptops, smartphones, and tablets.

[72] David Opie from Digital Spy reported that the show helped normalise the portrayal of gay sex on mainstream television.

The website's critics consensus reads, "Propelled by an exquisite cast, empathetic writing, and a distinct visual style, It's a Sin is an incredible feat of small-screen magic.

Olly Alexander's performance received a positive review from Josh Smith from Glamour, who branded him the "heart of the show".

[78] In another review, Suzy Feay of the Financial Times explained how "frivolous, bitchy Ritchie could easily be played as caricature, but Olly Alexander gives him a magnetic charm".

Similarly, Flora Carr from Radio Times described her performance as "stunning" and "heartbreaking", noting that some critics originally expressed confusion over Hawes' casting in the small role of Valerie, "a dowdy, cardigan-wearing Isle of Wight resident".

Of the character development she said "(Davies creates) real, flawed, entirely credible bundles of humanity and make it clear, without even momentary preachiness, how much they have to lose."

Mangan drew comparisons to the COVID-19 pandemic, expanding that in its wake she felt that people could "empathise that bit more with the fear, uncertainty and responses rational and irrational to the emergence of a new disease."

"[85] A review of the first episode in the Radio Times was also broadly positive, summarising that "Russell T. Davies portrays London's early 1980s gay scene as giddily optimistic – but foreshadows the AIDS crisis to come.

[89] James Delingpole from The Spectator branded Davies' casting of mainly gay actors "blatant hypocrisy" but thought the show was "hugely entertaining".

[90] Elton John praised the show as a "triumph of creativity and humanity", adding that it was a "moving testament to a pivotal and important moment in LGBTQ history.

[92] The Los Angeles Times gave a mixed review about the series, noting that while it claimed to be the first AIDS-related drama on British television, it actually wasn't.

The network was established in 1982 with a remit to “appeal to tastes and interests not generally catered for” by existing British broadcasters, and the wide range of queer work it commissioned included Derek Jarman's AIDS elegy “Blue” (1993) and Stuart Marshall's AIDS activist films “Bright Eyes” and “Over Our Dead Bodies.” If Davies found time to resurrect the Tombstone ad and the 1980s version of “Doctor Who,” why couldn't any of “It's a Sin's” lead quintet have been seen watching the British gay anthology series “Out on Tuesday”?

[94] El Hunt from music magazine NME noted that the series uses "a faultless selection of queer anthems and 80s smash hits that take on a new resonance.

"[95] Annabel Nugent from The Independent praised the soundtrack stating "it manages to produce a feeling more substantial than that generic, cookie cutter kind of nostalgia.