It follows an application last year from the MoD to build three more radomes at the site, which was also passed.
There are now over 30 distinctive radomes, or “golf balls”, at the secretive site. The radomes are believed to house satellites and transmitters.
Washburn Parish Council said it was concerned by the expansion, as well as the detrimental visual impact created by the new radome.
However, it said it “recognises the important security roll” that Menwith Hill plays.
In granting the application, council case officer Mike Parkes said the national security benefits of the radome outweighed its “harmful effects” on the Nidderdale landscape.
Built in the 1950s on the edge of Nidderdale, Menwith Hill is the United States’ largest overseas surveillance base.
Since 2000, protestors have taken part in a weekly demonstration outside Menwith Hill, which has been halted due to lockdown.
Sarah Swift, from the Menwith Hill Accountability Campaign group, said:
“We find the expansion of the site and of the base’s operations very worrying indeed.
“We believe that the activities of the base do not enhance the security of our area, our country or our world.”