Huawei's Meng Wanzhou flew to Shenzhen on Saturday evening, hours after two Canadians freed by China had gone back.
In 2018 China accused Michael Spavor and Michael Kovrig of espionage, denying detaining them was in retaliation for Ms Meng's arrest.
The apparent swap brings to an end a damaging diplomatic row between Beijing and the West.
Mr Spavor and Mr Kovrig arrived in the western city of Calgary just before 06:00 local time (12:00 GMT) and were met by Prime Minister Justin Trudeau.
A couple of hours later Ms Meng touched down in Shenzhen, China, to applauds from a crowd gathered at the airport.
"I'm finally back home!," said Ms Meng, according to the Global Times, a Chinese tabloid backed by the ruling Communist Party.
"Where there is a Chinese flag, there is a beacon of faith," she added. "If faith has a colour, it must be China red."
Ms Meng was wanted on charges in the US but was released after a deal between Canada and US prosecutors.
Before her release, Ms Meng admitted misleading US investigators about Huawei's business dealings in Iran.
She spent three years under house arrest in Canada while fighting extradition to the United States.