"Dad is returning on 10 August at Don Muang Airport," Paetongtarn Shinawatra said in a social media post, referring to an airport in the capital Bangkok. "This decision to come home is something that dad has seriously spoken about since the beginning of 2022."
Thaksin, 74, and the Pheu Thai party backed by his billionaire family remain popular among Thailand's working and rural masses, coming in second in the May 14 poll. Pheu Thai is trying to form a government and is expected to nominate a candidate for prime minister in the coming days.
He was premier from 2001 until his ousting in a 2006 coup and now lives in self-imposed exile after fleeing Thailand to avoid a jail sentence for graft in 2008.
Thailand's deputy national police chief Surachate Hakparn said Thaksin would be subject to the judicial process upon his planned return.
He faces up to 10 years in jail for multiple cases in which he was convicted by the country's supreme court, charges he says were politically motivated.
"The police will conduct their duties normally when the plane lands. He will have to go to court and listen to what they decide," Surachate told Reuters.
Thaksin had previously indicated he would return to Thailand in July.