The twin actions by the legislature and the attorney general against Yingluck are widely seen as an attempt by the military junta to cripple the political machine founded by Yingluck's brother, Thaksin Shinawatra, another ousted prime minister, and prevent them from returning to power.
The legislature voted 190-18 to impeach Yingluck for her role in overseeing a government rice subsidy program that lost billions of dollars. The vote results in her being banned from political office for five years.
Separately, the attorney general's office said it would indict her on criminal charges for negligence related to losses and alleged corruption in the rice program. If convicted, Yingluck could face 10 years in jail.
She was forced by a court ruling last May to step down from her job for illegally transferring a civil servant, and just days later the army staged a coup against her government.
On her Facebook page, Yingluck said she still wants to see reconciliation and democracy in Thailand strengthened, "even though today Thai democracy has died, along with the rule of law." She cancelled a scheduled news conference after her lawyers said the military authorities advised she risked violating martial law.
In her appearance before Parliament on Thursday, she denied she was responsible for any corruption and questioned the fairness of an investigation by the state anti-corruption commission, which had recommended charges against her.
The rice subsidy program, which paid farmers double the market price for their crops, ultimately incurred national losses of more than $4 billion and temporarily cost Thailand's place as the world's leading exporter.
After the army ousted her brother in 2006, Yingluck led the pro-Thaksin Pheu Thai Party party to victory in 2011 with an absolute majority of seats in the lower house.
The five-year ban on Yingluck's political activities "represents a show of confidence by the junta, which feels that it has broken the back of the Pheu Thai Party" and their supporters, the Red Shirt movement, said Kevin Hewison, a Thai studies expert who heads the Asia Research Centre at Australia's Murdoch University.
"With Yingluck banned and Thaksin in exile, the military junta and its appointed bodies will feel more confident in gradually preparing the way for an election, probably in 2016. They will be more confident that they can be heavy-handed in changing the political rules to prevent any pro-Thaksin party having any chance to do well electorally," he said.
A mass political protest by the Red Shirts remains unlikely for now, said London-based analyst Ambika Ahuja of the Eurasia Group consultancy.
"Thaksin will likely continue to hold off on any active political movement, maintaining a long-term strategy rather than pushing for an immediate end game. However, there will be a rise in anti-military rhetoric and more opponents will openly question the army's legitimacy," she said.
Associated Press writers Todd Pitman and Grant Peck contributed to this report.Suggest a correction