Gallagher is on loan at Palace from ChelseaLeeds United have condemned a homophobic chant aimed at Crystal Palace midfielder Conor Gallagher when the teams played on Tuesday.
The incident took place during the Premier League's Rainbow Laces campaign to support LGBTQ+ inclusion.
The Elland Road side won the game 1-0 following a late Raphinha penalty.
"We are aware of a homophobic chant directed at a Crystal Palace player and we want to be very clear that this is unacceptable," said a Leeds statement.
"We will continue to work closely with Marching Out Together (Leeds United's LGBT+ supporters' group) and all of our supporter groups to ensure that we do everything within our power to eradicate homophobia and any other form of discrimination from our football club."
Gallagher is on a season-long loan at Palace from Chelsea, whose official LGBTQ+ supporters' group said it was "disappointed" by the homophobic chant.
"This is not okay and should not be happening," said Chelsea Pride.external-link
"There is no place for homophobia, biphobia and transphobia in football or society.
"All forms of discrimination need to be kicked out of the game we all love.
"We need clubs and authorities to take a stronger stance towards those fans who use this language."
