To mark the occasion, the coach operator awarded two customers with a £500 holiday voucher.
Managing director Graham Rogers says: "Hitting the half-a-million-customer milestone just two years after our launch is an unbelievable achievement.
"I’d like to congratulate our lucky winners and thank every holidaymaker who has travelled with us over the past two years."
To meet an increase in demand for its breaks and holidays since its inception in April 2021, Caledonian Travel has opened five travel centres in Glasgow, Gateshead, Middlesbrough, Hull and Wakefield.
