The 74-year-old is in Bradford to film her new project The Duke, which tells the true story of the only successful theft of a portrait from the National Gallery.
Mirren, who won the Academy Award for Best Actress for her role in The Queen in 2007, has taken to Instagram to praise the city - describing Bradford as 'magic'.
She has shared a photo of herself backstage with Paul Chuckle of the Chuckle Brothers and fellow panto king Billy Pearce at the Alhambra, which she praised as 'magnificent', and even got into the panto spirit by wearing a flashing tiara.
Other snaps show her meeting a hen party in 80s fancy dress and enjoying a curry at Indian restaurant Mumtaz.
This year's Alhambra panto is Snow White and the Seven Dwarfs, and stars Chuckle - real name Paul Elliott - alongside Pearce and Faye Tozer of the pop group Steps.
Mirren and co-star Jim Broadbent have shot The Duke at several locations, including Bradford City Hall.
Bradford UNESCO City of Film confirmed they had spent several months sourcing and preparing sets.
The police museum beneath City Hall has a preserved Victorian courtroom and jail cells, while the nearby historic district of Little Germany is also popular with period productions.
The incredible heist that The Duke is based on
The Duke is set in 1961, when 60-year-old bus driver Kempton Bunton was accused of stealing Francisco Goya's portrait of the Duke of Wellington from the National Gallery in London - the only theft in the institution's history.
He sent ransom notes claiming that he would return the artwork if the government spent more on social care for the elderly and free TV licences.
He claimed he managed to get into the gallery through a toilet window after talking to staff and discovering the security system was deactivated for cleaning during the morning. He later contacted news agency Reuters to request a donation to a charity to fund TV licences for poorer people in return for the painting.
The ransom was declined and the painting was not seen again for four years, until Bunton contacted a newspaper and informed them he would leave the picture in the left luggage office at Birmingham New Street Station.
He was traced and arrested, but at his trial was only convicted of stealing the frame, which was still missing. His barrister successfully argued that he had never intended to keep the painting permanently so it had not been stolen. He was sentenced to three months in prison and the law was subsequently changed as a result of the case.
In 1996 it was first rumoured that another person may have actually committed the theft on Bunton's behalf, but it was not until 2012 that a confidential file was released by the National Archives which stated that in 1969 his son John had confessed to stealing the painting and reiterated that the intention had always been to return it. He said his father and warned him and his brother Kenneth not to come forward. No decision was taken to prosecute John for theft or Kempton for perjury.
Bunton died in 1976.