The 23-year-old has joined Norwich from Tottenham on a four-year contract for £8m.
He passed his medical on Tuesday night. Pritchard spent the end of last season on loan at West Brom but made just two appearances.
He announced on the club's website that he's ready to fight.
"I feel I need to go out and prove myself again in football. I'm 23 now so it's about time I had my own path really.
"I've had a full pre-season and with our first game at the weekend I'm looking forward to hopefully bedding myself in quickly".
City manager Alex Neil added: "Alex is an exciting player who is capable of both scoring and creating goals.
"He is proven at this level having excelled at Brentford two seasons ago, and adds to our attacking options. I'm really looking forward to working with him on a day-to-day basis.".