The Owls fans set up a fundraiser for the foundation named after the cancer victim following a controversial incident during the Championship match against Sunderland on Friday.
An image appeared on social media after the game of a man holding up a photo of the late six-year-old towards the travelling supporters.
Sunderland fan and mascot, Bradley, passed away in 2017 and became a famous figure as he developed a friendship with former Black Cats star Jermain Defoe before his passing.
Two men were subsequently arrested for a public order offence and a 31-year-old man has pleaded guilty at the Sheffield Magistrates’ Court on Monday. He will be sentenced in November.
In response to the controversy, Wednesday supporter Leanne Wood set up a fundraiser for the Bradley Lowery Foundation, which was set up by his family to help children suffering from neuroblastoma, and more than £20,000 has been raised so far.
Wood told The Mirror: "When I saw the images it made me feel sick to my stomach. The fact that Bradley's family had to see that is absolutely disgusting and heartbreaking.
"I felt like I wanted to actively do something about it. I put the idea of a fundraiser across to the members of the Sheffield Wednesday Women's Supporters Group who said they would back it all the way.
"I knew we'd get a response because being in the Wednesday community, I know the fans and the people of Sheffield in general have hearts of gold. We've now surpassed £18,000 which is just insane and shows what Wednesday fans are actually all about."
She added: "Bradley's story is absolutely heartbreaking but to know now that we have made a difference to other children that suffer with cancer is incredible. It will also go towards research of neuroblastoma, which needs a lot more awareness. It will change a lot of people's lives."