Much love, Banksy."
School head teacher Geoff Mason told the Bristol Post: "I think it went up over the weekend, and completed last night, but we're not entirely sure.
"It was done after we ran a competition to change the house names, and we decided to name them after Bristol legends. We had to include Banksy."
The other three school houses were named Cabot, Brunel and Blackbeard.
"We thought it would be a good idea to write to the PR company and let them know we've run the competition," Mason added.
"I'm sure this is Banksy's work. We had a call from his PR team, and a letter signed by him."
"We are very thrilled about it, and it's great for the school community.
"I'm sure it will inspire the children. The staff had to make quite a few calls this morning to make sure nobody cleaned it off.
"It really is amazing."