The Turin-based club have also been fined €10m and a further €10m will be added if they fail to comply with financial fair play rules for the next three years.
Juventus were docked 10 points by the Italian Football Federation back in May for falsifying their accounts.
That ruling saw them finish seventh in Serie A which was only good enough to secure them a spot in next season's Europa Conference League.
But the latest announcement from UEFA will see Juventus play no part in Europe's third tier club competition for the 2023/2024 season.
Fiorentina will now take Juventus' place in the Conference League.
A statement from European football's governing body read: “The CFCB First Chamber concluded that Juventus (ITA) violated the UEFA’s regulatory framework and breached the settlement agreement signed in August 2022. As a result, the CFCB First Chamber terminated the settlement agreement concluded with the club and decided:
“To exclude Juventus from the 2023/24 UEFA men’s club competition;
“And impose an additional financial contribution of €20 million on the club. Of this amount, €10 million is conditional and will only be enforced if the club’s annual financial statements for the financial years 2023, 2024 and 2025 do not comply with the accounting requirements as defined in Annex G of the UEFA Club Licensing and Financial Sustainability Regulations.”
