She was accused of using her influence with the president to win $560 million in government contracts.
Zapata, a former manager at the Chinese engineering group CAMC, was accused of using her influence with the president to win $560 million in government contracts.
She began dating Morales in 2005, when she was 18 years old. Morales, 57, said the affair ended two years later.
The case exploded into the headlines in February 2016, just as Bolivia headed into a referendum on whether to allow Morales, who is single, to run for a fourth term.
The leftist leader, who has been in power since 2006, went on to lose the vote.
Congress opened an investigation after the government admitted Zapata used state offices and employees to carry out CAMC business, but ruled Morales was not at fault.
La Paz prosecutor Edwin Blanco said Zapata was guilty of laundering "illicit earnings, which was proven based on the vast deposits in [her] accounts and cash payments that the defendant made to purchase real estate, autos and companies, among other things."
Blanco said Zapata was handed the maximum sentence possible in this case.
Four government workers who were her accomplices received lesser sentences.
The scandal took a bizarre twist when Morales and Zapata got into a bitter dispute over a child he allegedly fathered with her.
He said the boy had died, while she insisted he was still alive.
She ultimately changed her story, and claimed that the baby had died in 2009.
Five people were arrested for allegedly coaching a different boy to pose as the president's son.
In a recent TV interview, Zapata claimed to have been used since 2005 by an opposition politician who was aiming to hurt the president.