The Barcelona president believes the France international has more potential for greatness than the Paris Saint-Germain star.
Ousmane Dembélé is "much better" than former Barcelona star Neymar, according to president Josep Maria Bartomeu.
Neymar left Barca for Paris Saint-Germain in a world-record €222 million transfer in 2017 and Dembele arrived as his €105m replacement from Borussia Dortmund.
Dembélé has scored 11 La Liga goals and 18 in all competitions since moving to Camp Nou and Bartomeu heaped praise on the 21-year-old France winger.
"It's not possible for Neymar to come to Barcelona as we have another sporting project with Dembélé and [Philippe] Coutinho," Bartomeu told TVE ahead of Tuesday's Champions League quarter-final second leg against Manchester United.
"We are happy with what we have, as Dembélé is better than Neymar and he is a good professional player.
"He is a young guy who arrived at a huge club and that's not easy, but he has adapted and he is much better than Neymar."
Coutinho staying at Barça "unless release clause is met"
Philippe Coutinho has been linked with a move away having struggled to cement a spot in Barca's starting line-up since his €160m switch from Liverpool In January 2018.
United and Chelsea have emerged as possible destinations but Bartomeu said: "Coutinho is an excellent player and he has the coach's confidence.
"He has contract with us and he will remain at the team, unless they meet his release clause."
There are also doubts over the futures of Ivan Rakitic and Samuel Umtiti at the club, with the pair reportedly attracting interest from the likes of Inter, Arsenal and United respectively.
Bartomeu added: "[Rakitic] has a contract and we are very happy [with him]. I had a conversation with him in the summer and I told him that we could talk to improve his contract.
"We have not talked because of the calendar and because it's not easy due to the balance of wages, but we will talk with him. He's an indisputable player and he becomes better every year.
"[As for Umtiti] we renewed him before the World Cup; he has four years left on his contract and there is no Umtiti issue. Now he has to recover from his injury as we want to have him in the best form possible. Having Umtiti and [Clément] Lenglet on the left [side of central defence] is a guarantee and I would like him to continue."