Saudi Arabia will invest 300 billion baht in various industries, including tourism, energy and medical care, next year, according to a government spokesman.
Anucha Burapachaisri said Prime Minister Prayut Chan-o-cha was pleased to learn about the plan, which involves the Saudi government and private sector.
Mr Anucha said the Middle Eastern country is eyeing industries in the Eastern Economic Corridor (EEC), such as tourism, medical care, oil and construction materials.
The plan followed the restoration of diplomatic ties between Thailand and Saudi Arabia this year, he added.
During his first official visit to Thailand for last month's Apec summit, Saudi Crown Prince Mohammad bin Salman bin Abdulaziz toured the EEC, where many businesses focus on advanced medicine, processed food, clean energies and electric cars.
Thailand will become a hub for electric vehicle manufacturers in Southeast Asia due to the government's policy to attract investors in the EV manufacturing sector, he said, citing the EEC's strategic plan.
Many automakers have announced that Thailand is their EV production base, he said. Thailand also has workers who are experienced in auto-manufacturing, making the country ready to welcome the growing EV business, he said.
Mr Anucha said Gen Prayut expresses his gratitude to the private and public sectors for promoting Thailand's manufacturing business on behalf of its global interests.
He added that foreign investments will increase Thailand's ability to expand its industries and boost its economy in the long term.
"[The investment plan] is a result of the Thai-Saudi relationship that was restored by Gen Prayut's government," he said. "It is promising that there will be more grand-scale investments by allies of the Thai government."