The 21-year-old first started playing rugby at the Avon club in Bath at the age of five - and originally played on the wing - and also played at loosehead prop before being converted to hooker.
Hayes has gone on to make a big impact at Bristol where he established himself as first choice this season before injury.
Now he is eager to repeat that success at Warriors where he will work under the guidance of the coaching team of Richard Hill and Phil Davies.
"Worcester is a very good club with very good facilities so the next few seasons will be very exciting for me," said Hayes, who made 37 appearances for Bristol.
"I already know some of the boys, like Tom Arscott and Alex Crockett from their time at Bristol and also Ollie Frost from playing England Under-16s, so there are faces I recognise.
"I'm looking forward to working with Richard Hill again. When I worked with him for one season at Bristol I enjoyed the opportunities he gave me and also the chance this will give me to work with Phil Davies. You only need to look at the teams and players he has coached to know what an impact he can have on my career.
"I want to make an impact at Warriors and I'm keen to work with players like Aleki Lutui," added Hayes.
"He is a Tongan international and senior player that I know all about, having started both league games against Worcester this season. He's very strong and I can develop from having him around me, he is destructive on the field and in the scrum.
"I owe a big debt of thanks to Bristol. This is my third season with the club and I made my Premiership debut when I was 18-years-old with them.
"That is something I will never forget and I have always enjoyed playing for Bristol. Hopefully I can now finish the season for Bristol on a high."