When the new service starts from Southampton on 24 May it will be the first scheduled air link between the city and Gibraltar.
Four days later, Eastern will restore scheduled flights from Birmingham to Gibraltar, which were lost following the demise of Monarch four years ago.
Both services will operate on Mondays and Fridays, on a Embraer 190 e-Jet.
Eastern GM Roger Hage said: “This marks a major development in the network Eastern Airways offers as our first regular scheduled services to the Mediterranean peninsula adjoining Spain.
“The new services see both our return to Birmingham Airport as an operator while extending the growing number of destinations served from our Southampton hub.”
Minister for Business, Tourism, Transport and the Port of Her Majesty’s Government of Gibraltar Vijay Daryanani added: “The links with both Birmingham and Southampton will open up a new catchment areas’ for Gibraltar.
“Work by this Government to ensure that the tourism sector recovers and flourishes after this pandemic does not stop.
“The news will no doubt be welcomed by the local business community and the tourism, retail and hospitality industries. This Government is delivering air services to Gibraltar in an unprecedented manner and is committed to adding further routes and more carriers in due course.”