The Glasgow-based aqua-leisure facility provider will provide steamrooms, saunas, rasuls, hammams and ice fountains for the property’s ninth-floor rooftop spa.
Presidential suites will feature saunas, steam showers and ice fountains, with the whole spa and treatment area to cover 800sq m (8,611sq ft).
Designed by UK-based architects ReardonSmith, the new 175-room Four Seasons Baku is set to also feature a range of restaurants is due to open later this year.
The Baku contract is the latest to be signed by Barr and Wray, which has also secured an agreement to act as consultants on a six-star hotel in Istanbul, Turkey.
Once complete, the Istanbul hotel will boast around 50 heat experience cabins - including saunas and steamrooms - in addition to indoor and outdoor pools.
Barr and Wray managing director Alister MacDonald said: “We have seen a massive surge in the overseas demand for spas and pools, particularly in Eastern Europe and the Middle East.
“High-profile and ambitious projects such as this really help showcase our work and we recognise that tapping into markets such as this is the way to continue grow as a business.”