The founder of Lucketts Travel, headquartered in Fareham, is a public governor for South Central Ambulance Service.
The coach firm has been training its staff on how to use the newly-fitted defibrillator.
The equipment can also be used by any fire responder.
In an emergency, 999 callers will be given a code to access the defibrillator and instructions on how to use the machine.
David said: ‘When someone has a cardiac arrest, the quicker resuscitation starts, the better their chances of survival.
‘That’s why we were so keen to get a defibrillator and it’ll be available 24/7.
‘While we hope it won’t ever be needed, it’s reassuring to know it’s there just in case.’
The decision to install the equipment at Lucketts HQ has been welcomed by local heart charity, Wessex Heartbeat.
Chief executive John Munro said: ‘This is a fantastic idea and we’re thrilled to see Lucketts has taken the initiative to install a defibrillator on its premises.
‘We’ve seen first-hand the difference this piece of life-saving equipment can make.’