The Casablanca-born 26-year-old, whose real name is Taha Fahssi, was accused of threatening the journalist in an online row after the Arab star made controversial comments about cannabis.
"We'll meet in Belgium and you won't know what happened to you," the rapper had said in a comment on Instagram.
As well as the prison sentence, he was ordered to pay 50,000 dirhams ($4,900) in damages.
ElGrande Toto's lawyer Abdelfattah Zahrach said he was "partly satisfied" by the ruling but objected to the requirement to pay compensation.
The rapper "has not committed any criminal act against the plaintiff", he said, adding that they would discuss whether to appeal.
The artist sparked controversy in September by telling reporters after a concert: "I smoke hash -- so what?... It doesn't mean I set a bad example."
His remarks triggered anger in conservative Morocco, which bans recreational use of the drug despite being its biggest producer, according to the United Nations.
He was accused of "inciting drug use" and defamation, and publicly apologized to people "offended" by the comments.
ElGrande Toto, who is currently on tour in Senegal, has a huge following in the Arab world. He is the region's second-most streamed artist on Spotify, after Egyptian rapper Wegz.