The 23-year-old defender pled guilty to a charge of throwing a plastic tumbler, which caused injury to a woman, at the Dalkeith Miners Club in February this year.
Porteous, who has played more than 130 games for the Capital club, was fined £320 and ordered to pay the victim £200 compensation.
A statement from the club read: “Hibernian FC fully condemns the actions of Ryan Porteous
“Whilst observing the conclusion of the legal proceedings, the club investigated this internally.
“Hibernian FC fully understands the severity of this incident, as does Ryan, and he has been handed the maximum possible fine, alongside receiving punishment at Court.
"Hibernian FC expects the highest standards of responsible behaviour from its players and staff. This has been firmly reinforced to the player.
"This will now remain a private matter and Hibernian FC will make no further comment.”