The deal sees the group acquire Stoke Place country house hotel in Buckinghamshire, safeguarding over 50 jobs in the process.
Cairn Group, a privately owned business, already has plans in place to revitalise the 39-bedroom, 17th century property.
The group now owns and operates a portfolio of 26 hotels plus bars and restaurants across the UK from its HQ in Newcastle.
Richard Warren, Cairn Group’s finance director, said: “We take great pride in the venues and businesses within our portfolio and are thrilled to announce the addition of Stoke Place – a beautiful building in picturesque surroundings.
“We have developed a long-term financial plan which will involve making a significant further investment to revitalise the reception areas, bedrooms, dining, conferencing and wedding facilities.
“We’re excited to be able to honour the existing bookings, and engage with those guests. The vital improvements we intend to make to the hotel will ensure it meets and exceeds all expectations. Being part of the community is always our goal.
"This marks our first acquisition in 2016 and one of many new developments we have planned over the coming months at Cairn Group.”
Over the past five years, the group has spent over £40m acquiring and improving assets and increased employee numbers in that period to over 2,100, establishing it as a leading player in the privately owned hotel owner and operator market.