The controversial billionaire, twice elected premier and ousted in a 2006 military coup, went to the Bangkok City Pillar Shrine ahead of a three-day trip to Chiang Mai in the kingdom's north later in the day.
Scores of media camped out in front of the shrine where Thaksin, wearing a blue shirt and a neck brace, prayed from around 5:00 a.m. (2200 GMT Wednesday), according to an AFP reporter at the scene.
Later today, he is due to fly to Chiang Mai -- his home city and traditional political power base -- to meet family and supporters and pray at the graves of his relatives.
He was accompanied by his daughter Paetongtarn, now head of his Pheu Thai party, and her husband.
The 74-year-old politician returned to the kingdom in August after 15 years of self-exile and was immediately jailed for eight years on charges dating back to his time in power.
But his sentence was cut to one year by King Maha Vajiralongkorn within days of his return and last month, the government said Thaksin was eligible for early release because of his age and health.
The former Manchester City owner's return to Thailand came shortly after his Pheu Thai took power at the head of a coalition government that includes parties close to his old foes in the military.
The timing of his return led many to conclude a backroom deal had been struck to cut his jail time, a suggestion denied by the Pheu Thai-led government.
Ramet Rattanachaweng, spokesman for the royalist Democrat party, said the public would be watching closely to see if Thaksin is being given special treatment.
"He is on parole. If he gets something beyond regular regulations, the probation and corrections departments will have to explain themselves," Ramet said.
Thaksin is widely seen as still wielding great influence with Pheu Thai, and on his release last month, Prime Minister Srettha Thavisin said that "everyone in the government is ready to listen" to the veteran leader.
Srettha is due to visit Chiang Mai from Friday on his return from official visits to Germany and France, and told reporters in Paris he would meet Thaksin "if opportunity and time allow", according to public broadcaster ThaiPBS.
Pheu Thai spokesman Danuporn Punnakanta on Tuesday urged the party's MPs not to go and see Thaksin, saying they should be in Bangkok for Thursday's parliament session.
Thaksin is one of the most influential but divisive figures in modern Thai history.
A former police officer turned telecoms tycoon, he is loved by millions of rural Thais for his populist policies in the early 2000s but has long been opposed by the country's royalist and pro-military establishment.
The tussle for dominance between the establishment and Thaksin and his allies has largely defined Thai politics over the past two decades.