The event, on Thursday (February 25), marks the 40th anniversary of the publication of his masterpiece, Lanark.
A Gray Day Broadcast at 7.30pm will involve special guests including author Irvine Welsh, Trainspotting star Ewen Bremner and Franz Ferdinand frontman Alex Kapranos.
Also appearing will be Ali Smith, Yann Martel, Denise Mina and Gemma Cairney.
The broadcast will be hosted by Neu Reekie, with publishers Canongate and the Alasdair Gray Archive, and part of it has been filmed beneath the “Celestial Ceiling” mural the artist painted at the Oran Mor venue in Glasgow.
People are also being urged to change their social media avatar to a picture of Gray on the day.
Sorcha Dallas, of The Alasdair Gray Archive, said: “Gray Day was born of a desire to foster a continued dialogue with Alasdair through the rich and multi-faceted works he has left behind.
“Alasdair was an incredible man and we hope this tribute will allow his admirers a chance to reminisce while bringing his work to many more who have still to discover it.”
It is hoped the event will become an annual commemoration of Gray’s life and work.
Organisers said: “25th February 2021 is the first Gray Day, a celebration of the writer and artist Alasdair Gray, on the 40th anniversary of his masterpiece Lanark.
“We are encouraging people to change their social media avatar to an image of Alasdair on 25th February, as well as to share and talk about his work and what it has meant to them – using the #GrayDay hashtag.”
Gray died in December 2019 a day after his 85th birthday following a short illness.
The polymath wrote more than 30 books, all of which he designed and illustrated.
He created several murals in his native Glasgow, while his work is also on display in galleries ranging from the V&A to the Scottish National Gallery of Modern Art.
As well as in Oran Mor, his murals can be seen in the city’s Ubiquitous Chip restaurant and in Hillhead underground station.
His work included novels, short story collections, plays, volumes of poetry, works of non-fiction and translations, including his interpretation of Dante’s Divine Trilogy.
David McDonald, chairman of Glasgow Life, said: “The literary and artistic prowess of Alasdair Gray has rightly made him one of Scotland’s most revered artists.
“On the 40th anniversary of his landmark novel, Lanark, it is fitting that his home city pays tribute to his outstanding talent and Glasgow Museums is pleased to be part of the celebration.
“Alasdair often attributed many happy memories to his time spent at weekend art classes in Kelvingrove Art Gallery and Museum, and we are very proud to have a number of his works in our collection.
“These include hugely popular pieces from his acclaimed 1977 City Recorder series, some of which are on display in the Gallery of Modern Art (GoMA) and can be enjoyed as soon as our museums reopen.
“Gray Day is a wonderful way to allow Alasdair Gray’s fans to indulge their passion while providing an opportunity for new audiences to discover his work.”
Tickets for the broadcast are free via www.grayday.info