The day marked five years since a Hawker Hunter aircraft crashed during a display at the airshow, killing 11 men.
Adur District Council chairman Councillor Andy McGregor attended the service.
“This was a tragedy that struck at the heart of our local community, and the effects of it are still felt deeply today,” he said.
“It is incredibly important to have a place where people can turn to in times of grief.
“The memorial will stand as a lasting tribute to the 11 men who lost their lives at 1.22pm on August 22 2015.”
The memorial consists of 11 personalised arches and a bench where visitors can sit and pay their respects to the 11 victims of the 2015 tragedy.