They had been raped and beaten, while some showed signs of "mutilation", a statement from the Internal Security Forces said.
"This is the largest sex trafficking ring we've uncovered since the outbreak of the Syrian war," a Lebanese security source told AFP.
Police officers in the Mount Lebanon region north of Beirut "identified and arrested a group of people who made up Lebanon's most dangerous human trafficking network", the ISF statement said.
They "rescued 75 women, most of them Syrian nationals who had been subjected to beatings and psychological and physical torture, forced to perform sexual acts and had indecent images of them taken and distributed," it said.
Ten men and eight women guarding the apartments where the victims were kept have been arrested, the statement said.
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Two other suspects remain at large.
Speaking to AFP, the security source added that "an eight-month-old baby, likely the child of one of the rescued women, was also found".
Even before the Syrian conflict erupted in 2011, Syrian women had been pushed into the illicit sex trade in neighbouring Lebanon.
"However, as with any war, conflict has made Syrian women and children even more vulnerable," the source said.
"They pay the highest price."