The centre-back was seen laughing at and waving away Rangers players after the full-time whistle.
The Ibrox trio of Alfredo Morelos, Borna Barisic and Daniel Candeias were involved in an altercation with Livi’s Ricki Lamie. Captain James Tavernier and Andy Halliday got involved as well to try and end the situation.
Livingston won the game thanks to Dolly Menga’s first-half striker which lifted the West Lothian side above Rangers into third place in the Ladbrokes Premiership.
Tavernier told the Daily Record: ““Teams will celebrate how they celebrate but we just have to use that as fuel to improve ourselves and move on.
“Our players don’t need to be involved in anything like that. There will be players in certain teams who will try to wind us up. We can’t be seen to be reacting to that sort of behaviour.
“It is something we need to stay away from. It is going to happen. It is a big result for them against Rangers.”
Gallagher took to Twitter to hit back at Rangers, claiming players refused to shake hands at the full-time whistle and inferred a lack of professionalism from Steven Gerrard’s men.
He tweeted: “Based on the report in the Daily Record I thought only right to issue my own response. At no point did myself of (sic) any other Livingston player seek to taunt Rangers players over the result. As professional sportsmen we always aim to represent the sport and the club in the right light.
“However due to a few Rangers players refusing to shake hands at the final whistle with myself and team mates things did get heated. We are professional sportsmen who should act and respect our opposite numbers win, lose or draw.”