His father, Jorge Messi, was also sentenced to 21 months in prison for defrauding Spain of €4.1m (£3.5m; $4.5m) between 2007 and 2009.
READ ALSO: Messi Tax Trial Starts In Barcelona
A Barcelona court found Messi, and his father, guilty of three counts of tax fraud, a statement from the court on Wednesday said.
They also face millions of euros in fines for using tax havens in Belize and Uruguay to conceal earnings from image rights – although neither are likely to serve any jail time.
During the trial, Lionel Messi insisted he “knew nothing” about the management of his financial affairs, saying his father dealt with them while he was “playing football”.
In his part, Jorge Messi claimed he did not have enough knowledge to orchestrate such a fraud, blaming his tax consultants instead.
READ ALSO: Messi Claims Innocence In Tax Fraud Case
In a statement issued today, the court also said that the sentence can be appealed through the Spanish Supreme Court.
Under Spanish law, a prison sentence under two years can be served under probation; meaning Messi and his father are unlikely to go to jail.
The court ordered Messi to pay a fine of around 2 million euros ($2.21 million) and his father to 1.5 million euros for the crimes.
The 5-time FIFA World Player of the Year had retired from international football in June 2016.