Carrickfergus station was evacuated on Tuesday evening after a member of the public carried a suspicious object into the inquiries office.
A number of local residents in the Larne Road area were also moved from their homes and officers from the bomb squad were tasked to investigate.
Police said a controlled explosion was carried out and the object was found to be a hoax.
All roads have now been reopened and residents have been allowed to move back in.
Local councillor Charles Johnston said the alert caused a lot of disruption to traffic, businesses and people in the area.
"I understand somebody walked into the station at around 7.50pm with a package and left it there," the DUP representative told UTV.
"It's very worrying. A lot of people walk along the seafront on a good evening like this and the businesses - the bar next door has been evacuated, people taken from their homes and traffic has been re-routed right around the town. It's caused a lot of disruption."