Tony Kenway, originally from Southampton, was killed in a car park in the resort of Pattaya at 14:10 local time, according to the Bangkok Post.
The Foreign and Commonwealth Office (FCO) has confirmed it is in contact with local police regarding the death of a British national.
Sanit Sport Club, where the shooting happened, offered its condolences in a message posted on its Facebook page.
It read: "We are very sad to announce the death of Tony Kenway who lost his life this morning. We would like to offer Tony's family and friends our deepest sympathy and condolences at this difficult time. RIP Tony."
The Bangkok Post reported that an eyewitness described the gunman as a "chubby man wearing a white T-shirt and black jacket" who opened the door of the red Cayenne GTS before firing once and escaping on a black motorcycle.
Mr Kenway was described as a father-of-four who had set up a website design business.
His Facebook profile shows he lived in Bangkok but previously resided in Marbella, Spain, and had been married to his wife, Pans, since November.
A FCO spokeswoman said: "We are in contact with the family of a British man following his death in Pattaya, Thailand. Our sympathies are with them at this difficult time. We are in touch with the local police."
A British man has been shot dead in his Porsche in Thailand.