A private jet carrying Thaksin landed at Don Mueang Airport in Bangkok at around 9 a.m. Hundreds of supporters had gathered outside the airport to welcome Thaksin.
"It's time for me to be with the Thai people," he told Nikkei Asia on Tuesday morning at Singapore's Seletar Airport before flying to Thailand.
Thaksin was taken from the airport to the Supreme Court, where he received a combined sentence of eight years on three corruption charges.
He was brought to Bangkok Remand Prison to await parole or pardon as parliament convened to vote on the nomination of Srettha Thavisin, a confidant of Thaksin, for prime minister.
For more than 20 years, and even in his absence, Thaksin has been a dominant figure in Thai politics. Flush with his telecommunications fortune, he held audiences with influential Thai figures in cities like Dubai, Singapore and Hong Kong -- his frequent haunts -- and remained outspoken on social media platforms such as X, formerly known as Twitter, and Clubhouse.
"I am free to travel anywhere in the world, but I have been jailed away from my family. If I come back and have to enter a smaller jail, it does not matter," Thaksin told Nikkei in March.
Until this year, parties associated with Thaksin had won every election since 2001, when he swept to power with the Thai Rak Thai Party. His sister Yingluck Shinawatra, similarly in self-exile over a five-year prison sentence, was the last Pheu Thai prime minister before the most recent coup in 2014.
Political observers doubt that the 74-year-old will spend much time behind bars. Convicted individuals aged over 70 in Thailand are eligible to request parole or a royal pardon.
"Without a settlement of the Thaksin factor, there will be no reconciliation," between his populist camp and the conservative and military establishment said Thitinan Pongsudhirak, director of the Institute of Security and International Studies at Chulalongkorn University.
The political trades that have followed the Thai election on May 14 may turn out to be Thaksin's ultimate deal. Pheu Thai set a goal of more than 300 lower house seats in the election to install a prime minister without being thwarted by the military-appointed Senate. That plan was upset by the progressive Move Forward Party, now considered by voters a more suitable carrier of the pro-democracy mantle than Pheu Thai.
But now, three months since the election, Pheu Thai is in pole position to form a government after leaving the Move Forward camp and aligning itself with parties led by the generals who ousted Yingluck. By Tuesday's end, the party could hold the premiership again if parliament approves its candidate.
But after losing reform-minded voters to Move Forward, Thaksin's homecoming could further damage Pheu Thai's democratic credentials in future elections.
"Pheu Thai is not the main show anymore," said Thitinan. Thaksin's previous electoral victories hinged on class and geographical divisions, but "Thai politics have moved beyond that. Now it's about structural reform," Thitinan said.
Nattawut Saikua, leader of the "Red Shirt" pro-democracy movement, ended his association with Pheu Thai on Monday over its alliance with the military-linked Palang Pracharath and United Thai Nation parties.
"There are certainly elements within Pheu Thai that would prefer to see it positioned as post-Thaksin rather than a pro-Thaksin party," said Duncan McCargo, professor at Singapore's Nanyang Technological University and author of a book on the former prime minister.
"Some Pheu Thai supporters can accept the logic that the party needs to take a pragmatic road back to power and place primary importance on Pheu Thai securing key economic ministries so they can address core livelihood concerns and grievances," McCargo said. "But for hard-core Red Shirts and those who have always seen Pheu Thai as an ideological party engaged in a struggle on behalf of the underdog, this kind of deal-making is a betrayal."