Port have appointed Scott Cooper as coach, the Thai League 1 club said on Tuesday.
The Englishman is Port's first foreign coach in six years after Japanese Masahiro Wada and Gary Stevens of England.
Cooper, 52, has previously coached Thai League 1 side Buriram United, Muang Thong United and Police Tero.
His most recent job was as coach of the Philippines.
Port chairwoman Nualphan Lamsam said it took quite a long time for the club to settle for a foreign coach.
"We want to create a new atmosphere in the team," she said.
"Cooper knows and understands Thai football. He also has experience in coaching at the international level as coach of the Philippines. With his experience, he will help us reach the target.
"I'd like to ask our fans to give him and his staff support."
Since Nualphan became chairwoman of the club, the Port Lions have used about one dozen coaches including Kiatisak Senamuang, Dusit Chalermsan and Jadet Meelarp.
Nualphan is also manager of the Thai men's senior and U23 national sides.
Some Port fans have called on her to quit the job to focus solely on the club.
Port have signed two new players, Hamilton Soares and Frans Putros.
Brazilian striker Soares, 31, was the top scorer in Thai League 1 last season after netting 19 goals for Nongbua Pitchaya while Iraq right-back Putros, 28, played in the Danish Super League for Viborg.
Port finished eighth in Thai League 1 last season.
Meanwhile, Buriram United stars Supachai Chaided, Suphanat Mueanta and Rattanakorn Maikami left for England yesterday to train with Leicester City for one month.
They will return before Buriram, who won the Thai League 1, FA Cup and League Cup titles last season, take on BG Pathum United on Aug 6 in the Thailand Champions Cup, the new season's curtain-raising match.