McDonald's franchisee Richard Marcroft installed the new machines on the wall outside of each restaurant and they are available to the public and all emergency services 24 hours a day.
Mr Marcroft said: "I'm delighted that we are able to support our communities with the defibrillators.
"We felt it was important to make this investment in our restaurants to help people if the worst was to happen.
"I'm keen to raise awareness of the defibrillators in the local community, so that people have peace of mind that this valuable technology is close at hand."
All McDonald’s managers are also trained in CPR and how to use a defibrillator.
The importance of CPR training and defibrillators made international headlines last summer when footballer Christian Eriksen collapsed and suffered cardiac arrest during a match at Euro 2020.
In December, Scarborough' s emergency services united to launch an awareness campaign to install more life-saving defibrillators across the region.
Locations of Defibrillators in Scarborough
Limited Access; where a building is required to be open:
• Scarborough College - Filey Road
• Scarborough Town Hall - St Nicholas Street
• Scarborough Rugby Club - Scalby Road
• Barrowcliff Pharmacy - Wreyfield Drive
• Plaxton Court - Woodlands Drive
• Osgodby Community Centre - Osgodby Lane
• Browns Caravan Park - Cayton Bay, Mill Lane
• North Cliff Crown Green Bowling Club - Peasholm Road
• McDonald's - Huntriss Row
• McDonald's - Eastfield, Dunslow Road
• Borough Bowling Club - Manor Road
• Scarborough Railway Station - Valley Bridge Road
• Scarborough RNLI Lifeboat Station - Foreshore Road
• Telephone Box Scalby - High Street
• Ambulance Station - Queen Margaret's Road
• Dexters Surf Shop - Peasholm Gap
• Cayton Bay Playing Fields - Carr Lane
• Side wall of shop 1 - Curlew Drive
• Seamer Sports Association - Pasture Lane
• Seamer and Irton Memorial Hall - Main Street
• Scarborough Yacht Club - Vincent Pier
• Oliver's Mount Circuit Office