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, reported Radio 24syv.
A Copenhagen Police spokesman told the radio station that he wouldn’t comment on the case.
The man is being cited under Article 136 of the Danish Penal Code, which outlaws “publicly approving” actions that are punishable under the nation’s terror laws. The penalty can range from a fine to two years in prison.
Radio 24syv reported that it found many other examples of Danish Muslims directly or indirectly celebrating the terror attack in Paris.
Two other Danish citizens were cited for the same violation in December. One had posted photos on Facebook of himself posing with severed heads while the other is accused of spreading "extremist video material" on the internet.
For much more on the Charlie Hebdo attack, which left 12 dead including 10 employees of the satirical weekly, and its dramatic aftermath, head over to The Local France.