The Copenhagen City Court also sentenced the man to conditional deportation, which means he will be kicked out of Denmark if he commits any new crimes.
Prosecutors had pushed for a five month sentence followed by actual deportation.
The man posted a link to a story on the Paris attack accompanied by a smiley face and comments in Arabic that said God deserved the honour for the killings.
In court, he tried to defend the Facebook post by saying he was merely displaying his faith.
“I just praised Allah. I do that every day,” the man said, according to broadcaster DR.
The Iraqi was a former spokesman for the organization Called to Islam (Kaldet til Islam) and it was revealed in court that he had been sentenced last year for threatening to decapitate the chairman of the Danish Syrian Association.
See also: Syrian conflict playing out in Denmark
The man was cited under Article 136 of the Danish Penal Code, which outlaws “publicly approving” actions that are punishable under the nation's terror laws. The man's lawyer argued that the Facebook posts were private and visible only to his 50 friends on the social network. The Iraqi also said he removed the posts after one of his friends warned him that they could be misunderstood.
The man's lawyer filed an immediate appeal against Wednesday's decision.