Munir has been brought in to replace last season's top goalscorer Paco Alcacer, who moved in the opposite direction in a 30million euros (£27.3million) deal - with a further two million euros in add-ons - last week.
On joining Los Che, the versatile forward told the club's official website: "When I knew about the offer from Valencia I had no doubts, I am very happy to be here, I have liked Valencia for a long time and I want to give everything for this shirt."
Munir believes Valencia can finish strong enough to qualify for next season's Champions League, adding: "I think we are going to achieve it. I am a striker that likes to score goals.
"I am here to work hard and help the team to do well. I am very happy here, concentrating on the team and our targets."