The rock legend is also expected to address the survivors in attendance at next week's show.
"We've been told that Paul McCartney will say something about Lac-Megantic during his concert but we don't know yet what he'll say exactly," said Rachel Dupuis, a spokeswoman for concert promoter 3 E Event, Experience, Emotion.
The idea was floated to McCartney's team by promoter 3 E at the beginning of the week. The former Beatle's entourage quickly agreed.
"We want to give a moment of respite, a few hours of pleasure which will perhaps take their minds off the tragedy into which they have been plunged in the last two weeks," said Daniel Gelinas, director general of 3 E in a statement released Friday.
The offer was communicated to Lac-Megantic Mayor Colette Roy-Laroche earlier this week and the promoters said municipal officials appreciated the gesture of support.
The tickets will be distributed in Lac-Megantic on Saturday, the two-week anniversary of the disaster.
The exact number of tickets isn't yet known but organizers expect it to be about 1,000.
It's believed unlikely that Stevie Wonder will appear even though he quipped during a recent Quebec City show that he and McCartney would do something together for those affected by the catastrophe.
After dedicating his concert last Sunday to the Lac-Megantic victims, Wonder suggested during his show he might perform with McCartney to help survivors. Organizers have since described the proposal as a "a total surprise" and no firmer details have emerged since.
McCartney is the latest notable to express support for Lac-Megantic. Others have included U.S. President Barack Obama, the Queen and Pope Francis.
A runaway train loaded with crude oil careened into the picturesque town early on the morning of July 6 and jumped the tracks in the community's downtown. The train exploded in searing fireballs that destroyed a wide swath of stores, homes and government buildings.
Quebec provincial believe 47 people were killed. About 2,000 people were forced to flee the area, although most have been allowed to return home.
McCartney's "Out There" tour will take over the historic Plains of Abraham in Quebec City on July 23.
He previously packed the site in 2008 as part of celebrations to mark the provincial capital's 400th anniversary.
The entertainment community in Quebec has already sought to help the stricken town with benefit concerts and another one, with a galaxy of Quebec stars, was announced on Friday.
The latest effort will be held at Montreal's Bell Centre on Aug. 13. Among the music acts confirmed so far are Garou, Isabelle Boulay, Coeur de pirate and Jonas & The Massive Attraction.
Jonas, who goes by his first name professionally but whose last name is Tomalty, is an ambassador for the Lac-Megantic region as are the concert's organizers, Peter MacLeod and Gino Chouinard.