A celebrated author from Zimbabwe, Tsitsi Dangarembga, was found guilty of inciting violence by toting a sign that demanded political reform.
The magistrate argued that by encouraging others to join, the protest may have disturbed the peace.
In exchange for avoiding a three-month jail sentence, Ms. Dangarembga consented to pay a fine of approximately $220 (£200).
In a trial that critics claim is the most recent example of a government crackdown on dissent, she had entered a not guilty plea.
This is despite the fact that President Emmerson Mnangagwa took power in 2017 with a promise to introduce reforms after the decades-long repressive rule of his predecessor, Robert Mugabe.
Ms Dangarembga is one of Zimbabwe’s most famous authors. Her novel, This Mournable Body, was shortlisted for the Booker Prize, in 2020.
She was convicted along with a friend Julie Barnes.
The pair had walked along a road in the capital, Harare, two years ago, holding placards that called for political reform and the release of two government critics.
The courtroom gasped and the two women stood motionless as the verdict was pronounced.
“Guilty of inciting public violence and breaching the peace,” came the judgment.
The magistrate said that as they protested on a public road and pictures were shared on social media, others could have been provoked to protest.
The two have until Tuesday to pay the fine. If they re-offend within the next five years they will be jailed for six months.