The Italian club were charged by UEFA in the wake of last week's Europa League game against Borussia Monchengladbach.
And, after incurring fines for similar incidents during group-stage games with Maribor and Tottenham, Lazio have been hit with a heavier punishment.
The ban on supporters will apply for the home leg of their last-16 tie with Stuttgart and the club's next game in European competition.
A fine of 40,000 euros has also been imposed for "the setting off and throwing of fireworks, racist behaviour and insufficient organisation."
Turkish club Fenerbahce, meanwhile, will host last-16 opponents Viktoria Plzen in an empty stadium after their fans threw fireworks during last week's game against BATE Borisov.


 





