The monument honors those who died in the fire at the Valley Parade Home in Bradford City on May 11, 1985.
The tragedy claimed 56 lives, including 54 Bradford City fans that day and two supporters of the opposition, Lincoln City. Another 258 people were injured.
The memorial, which was installed in 2010, was damaged earlier this week.
It's currently being repaired.
The club is scrutinizing CCTV footage and is working closely with authorities to bring criminals to justice.
The Valley Parade monument has been repaired and can be seen here on Thursday afternoon (Image: T&A)
A Bradford City spokesman said this afternoon, “Bradford City AFC is disgusted and disgusted by the damage caused this week at Bradford University Stadium Valley Parade Fire Memorial.
“It's not going well enough to say that this act is completely unacceptable — it's not entirely understandable.
“This monument is sacred to our club, our supporters, and to our people of Bradford.
“It is a place of memory and reflection, honoring the 56 Bradford and Lincoln City supporters who lost their lives in the Valley Parade Fire disaster, as well as the hundreds of people who have suffered life-changing injuries.
“Since its careful installation in 2001, the monument has tended to be cleaned daily by staff and maintained with the utmost care and respect.
“For someone to taint or damage it in any way is not only an attack on the physical compliment, but a dishonorable shaming to the memories of those we have lost and the families and communities that are still affected.
“We are working closely with local governments to review CCTV footage and identify responsible personnel.
“We do everything in our power to ensure that justice is accomplished.
“The damage has since been repaired, but the pain this caused simply cannot be reversed.
“We stand together as a club and as a city that denies this shameful act.
“We urge those with information to come forward and help bring the person responsible to court.
“The Bradford City AFC does not tolerate such disrespect.
“We always remember.”
The news of vandalism has prompted a fierce backlash on social media.
One commenter from X said, “There is no word to properly explain how disgusting these people are. They must face the full power of the law and throw books on the ground. The absolute scum of the earth.”