One section of the application focuses on the potential economic impacts.
It states that the club already attracts about 10,000 international visitors each golf season making it “one of the most significant tourism drivers” in the Mourne area and Northern Ireland as a whole.
It adds that independent research suggests the Open in Portrush last year had “a total economic impact of £89.2m” to Northern Ireland.
The Royal County Down plans have already been the subject of a public consultation.
They will now be considered by the planning committee of Newry, Mourne and Down District Council.
Work on the scheme could begin in the 2027 off-season, subject to planning.
The standard of the course is only one element of qualifying to host the Open.
The event’s organiser, the R&A, also need to see evidence that the venue has infrastructure to safely host tens of thousands of spectators.