Bobby Adekanya, 18, was abused while playing for the Reds' Under-19 side against Spartak in the UEFA Youth League in September.
A UEFA statement read: "The control, ethics and disciplinary body upheld Liverpool's subsequent complaint and a section of Spartak's stadium will be closed for their next home game in Europe.
"Spartak Moscow shall inform at least seven days prior to the match the sector to be closed, which shall at least comprehend 500 seats."
The Russian champions have also been fined €33,000 for holding up a 'UEFA Mafia' banner, setting off fireworks and blocking stairways during their 1-1 draw with Liverpool in the Champions League last month.
Spartak will have to display a UEFA banner saying '#EqualGame' in the closed section of the Otkrytiye Arena.