The event, which would have raised funds for the club's charity Foundation, was due to take place at St James' Park on Wednesday evening, four days before the final-day fixture against West Ham.
A club spokesman said: "Newcastle United Football Club has made the very difficult decision that in view of the current league position, it would not be appropriate for the team and coaching staff to be celebrating the season and collecting awards at a time when our only focus is on the next two games and securing Premier League status."
It is not yet known if the dinner will be rescheduled, but the club has vowed to work with Foundation to find another way to provide support.