Often hailed as a 'national treasure' for her decades as a popular cartoonist, writer and illustrator of children's books, it's taken four years by Jane Sellars, Harrogate Borough Council's curator of cultural services, to finally secure this exciting coup for Harrogate.
Jane said: "I'm really thrilled that Posy is exhibiting at Mercer this year. I've always been a big fan of her work and first approached her about it four years ago.
"She first came to Harrogate to meet me to talk about it a couple of years ago. She's a genius in bringing art and writing together."
Born in Berkshire and aged 72, Posy Simmonds is one of the world’s most known graphic novel authors, her work loved by millions.
After starting as a cartoonist in the national press in the late 1960s, she went on to create her most famous character Tamara Drewe as a comic strip in The Guardian in 2005.
Inspired by Thomas Hardy's novels, Post's witty stories of the glamorous columnist who shakes up the sleepy middle class village where she was born went on to become a successful graphic novel, then an international hit movie directed by award-winning Stephen Frear and starring Gemma Arterton.
The retrospective exhibition is expected to be the biggest blockbuster success for this publically-owned gallery in Harrogate since the Atkinson Grimshaw show in 2011 which attracted record attendance figures and received wide acclaim on the likes of BBC Radio 4.
The Harrogate gallery has also commissioned Posy to produce a drawing about the Mercer which will be given pride of place in the new exhibition.
Jane Sellars said: "When Posy came to Harrogate, she had a good look round all our great places such as the Royal Pump Room, the Valley Gardens and the Royal Hall.
"Her work is acutely observant of people, their behaviour, language, appearance.
"She has this brilliant understanding of modern British culture which she interprets in her work.
"She's the perfect commentator on social class, especially, the British middle class."
Posy Simmonds: Original Artwork and Unseen Sketches will run at the Mercer Gallery from June.
The artist herself will also be coming to Harrogate for an 'In Conversation with' in September.
Posy also drew the illustrations for the opening titles of the BBC's 2007 production of Elizabeth Gaskell's Cranford.
Posy Simmonds: Original Artwork and Unseen Sketches, Mercer Gallery, Swan Road, Harrogate, Saturday, June 16 to Sunday, September 9.
Posy Simmonds In Conversation Paul Gravett (journalist, author and all round expert on comic publishing and illustration), Monday, September 3.
Supported by the Friends of the Mercer Art.