Kate Winslet was originally cast, but dropped out.

Olivia Colman gained 2.5 stone (16 kg. or 35 lbs.) to play Queen Anne.

Costume designer Sandy Powell intentionally used anachronistic fabrics. Laser-cut lace and vinyl was used for many courtiers' clothes. The servants' dresses and britches are made from denim recycled from thrift store jeans from throughout England. Queen Anne's dressing gown is made from a chenille blanket that Powell found on eBay.

Sarah Churchill, the Duchess of Marlborough, is the direct ancestor of both Sir Winston Churchill and Princess Diana (born Diana Spencer). The former was born in Blenheim Palace, which is unfinished in the film, and was named after Sarah Churchill's father-in-law, the first Sir Winston Churchill. Before becoming prime minister, he wrote a biography of Sarah Churchill's husband, the first Duke of Marlborough.

The wigs had their own trailer.

The film was shot mostly with available sunlight or practical lighting, such as candles and fireplaces. Robbie Ryan kept backup lighting equipment on stand-by, but used very little additional light, mostly due to unseasonably warm weather during filming.

The film doesn't mention it, but Abigail was Robert Harley's cousin.

According to Rachel Weisz, The Favourite is "like a funnier, sex-driven All About Eve (1950)."

This is the first time Yorgos Lanthimos directed a film in which he is not the screenwriter and nor is his regular partner, Efthymis Filippou.

Winston Churchill was born in the palace Queen Anne built for Sarah Churchill in 1874, 166 years after the movie takes place. The Churchill family continued to live in Blenheim Palace for 300 years.

Queen Anne's husband Prince George of Denmark (father of all her ill-fated children) is never seen or mentioned, although Abigail entered the queen's service in 1704 and George did not die until 1708. His death, as well as the deaths of their children, was among the reasons for Anne's depression which the film depicts so graphically.

Some of the films that inspired Yorgos Lanthimos were Possession (1981), Cremator (1969), Cries & Whispers (1972), Amadeus (1984) and The Draughtsman's Contract (1982).

All three of the main characters vomit at least once in the film.

Filming took place at Hatfield House in Hertfordshire and Hampton Court Palace, Richmond upon Thames, between March and May 2017.

Costume designer Sandy Powell had to divide her duties between this film and Mary Poppins Returns (2018). Fortunately, both productions used adjacent workspaces at Pinewood Studios.

Most of the costumes and wigs were made from scratch. The budget was very tight, so renting them was not feasible. The early 18th century is rarely depicted on film, so few costume houses had much appropriate stock available. Clothes and wigs were custom built, then deconstructed and re-used in other scenes.

The film's cast includes two Oscar winners: Emma Stone and Rachel Weisz.

Marks the second film of 2018 that Rachel Weisz took over a role from Kate Winslet, the other being The Mercy (2018).

This is the second film collaboration of director Yorgos Lanthimos with actresses Rachel Weisz and Olivia Colman after The Lobster (2015).

This is the second film that Rachel Weisz and Nicholas Hoult have starred in together. The first was About a Boy (2002).

According to makeup designer Nadia Stacey, Nicholas Hoult named all of his wigs. His main wig was Barbara (or, more frequently, Babs). The orange wig he wears when he watches courtiers throwing pomegranates at a nude Tory is Lulu. Another was named Hattie. Hoult also became very attuned to how Harley might wear beauty spots, depending on the situation or the message his character was trying to convey. "Nick and I would sit every day and look at the scene and say, 'We should do it here now because you're going to see the Queen,'" said Stacey. "We really played with that."

When designing for the character of Lady Sarah Churchill, Sandy Powell used Katharine Hepburn as a reference point.

Loosely based on actual events.

Yorgos Lanthimos's third English language film after The Lobster (2015) and The Killing of a Sacred Deer (2017).

The characters eat lobster and venison (deer meat). Yorgos Lanthimos's two previous films were The Killing of a Sacred Deer (2017) and The Lobster (2015).

Queen Anne keeps pet rabbits in her bedroom. Olivia Colman, voices Strawberry, and Nicholas Hoult voices Fiver, in Watership Down (2018).

Filming began March 20, 2017.

In conjunction with the film's UK release, several of the film's costumes were put on display in The Queen's Gallery at Kensington Palace, London. The exhibit opened December 14th, 2018, and ends in February 8th, 2019.

The film is a co-production of Ireland, the United Kingdom, and the United States.

Fox Searchlight Pictures acquired distribution rights to the film in May 2017. It screened at the Telluride Film Festival on September 2, 2018. It was the New York Film Festival's opening night film 28 September 28, 2018. It opened the BFI London Film Festival on October 18, 2018. It got a limited release in the U.S. on November 23, 2018 and in the UK on January 1, 2019.

Robbie Ryan briefly left the film midway through shooting because his father died. Stephen Murphy stepped in as director of photography.

The film premiered at the 2018 Venice Film Festival, where Olivia Colman won the Volpi Cup for Best Actress. Willem Dafoe won the Volpi Cup for Best Actor the same year, for his role in At Eternity's Gate (2018).

Sandy Powell previously worked with Dien van Straalen on Orlando (1992), part of which is set in the early 18th century. Orlando's scenes that take place in 1700 were filmed at Blenheim Palace, depicted in model form at the beginning of this film.

Emma Stone's topless scene was not scripted. It was her idea, and she had to convince Yorgos Lanthimos to allow it. She argued that it would be much more humiliating for Sarah to see Abigail topless rather than just under a sheet.

Although Lady Sarah ultimately loses her position of power and influence over Queen Anne and the parliament of her day, her descendant Winston Churchill became the Prime Minister, and Prince William, her descendant through the Spencers, will likely become king.