A video shows Lafferty posing for a photo with a supporter – after which the supporter expresses his support for Celtic, the reigning Scottish champions, a club traditionally supported by Catholics.
Lafferty, who played for Celtic’s arch-rivals Glasgow Rangers – a traditionally Protestant club – responds with a disparaging statement of Catholics and Irish nationalists.
According to the SFA, Lafferty is guilty of “offensive language, referring to a person’s religion or belief” as well as “indecent or insulting words or behaviour”.
Lafferty, who now plays for Scottish side Killmarnock, is remorseful.
“There is no excuse. I immediately regretted it, since then I have been ashamed. I fully understand that I should not have responded to provocation in this way,” he is quoted as saying Belfast Telegraph.
The suspension comes into effect with immediate effect.
Lafferty has 89 caps for Northern Ireland on his record, according to Transfermarkt.