Joel Richards, aged 19, uncle Adrian Evans, 49, and grandfather Patrick Evans, 78, all lost their lives in the coastal city of Sousse when the attack took place on June 26.
As a mark of respect, 17-year-old Aston Villa supporter Charlie Cox launched a fundraising campaign to buy a banner he hopes will be displayed at the Banks's Stadium on July 25 - the day Walsall host Villa in a pre-season friendly.
The banner, which will cost £225, will read 'Rest in Peace Joel Richards, Adrian Evans and Patrick Evans. Rivals on the Pitch, Always United Off It'.
Charlie said: "We have all been shocked and saddened by what happened in Tunisia with three generations of the same family being killed.
"I think it's so important that in these times the entire football family comes together.
"We have an annual pre-season friendly with Walsall and I felt it was my duty as part of the Midlands football family to do something for Joel, Adrian and Patrick.
"I wanted to show Walsall's fans and the family members of those who lost their lives that we are thinking about them at this very sad time."
Charlie launched the campaign on Monday and the £225 target was reached this morning, 24 hours ahead of the deadline at noon tomorrow in order to have the banner made in time for the game.
"I've teamed up with the Villa website 'My Old Man Said' to help raise the funds," the 17-year-old said.