Residents of the village fled as rebels seized control of it last month.
Kardashian appeared to have bolstered false claims by loyalists of Syrian president Bashar Assad, who said Syrian rebels desecrated the village's churches and slaughtered residents.
She used the SaveKessab hashtag that was used to spread the false claims, causing its popularity to explode.
"If you don't know what's going on in Kessab please Google it ... As an Armenian, I grew up hearing so many painful stories," Kardashian wrote, using an alternate spelling of the village's name.
"Please let's not let history repeat itself!!!!!! Let's get this trending!!!! #SaveKessab #ArmenianGenocide," she wrote.
The celebrity of Armenian descent underscored how Syria's war, more than any other in history, has been waged on social media, with both supporters of President Assad and those opposing his rule using selectively-chosen videos and photos, sometimes faked, recycled or altered, to support their grievances.
Kardashian's use of the two hashtags side-by-side, "SaveKessab" and "ArmenianGenocide", suggested she was also linking the flight of most of Kassab's 2,000 residents to the deaths of an estimated 1.5 million Armenians by Ottoman forces in the early 20th century.
The event is widely viewed by scholars as the first genocide of the 20th century. Turkey denies that the deaths constituted genocide, saying the toll has been inflated and those killed were victims of civil war and unrest.
Kardashian's publicist Ina Treciokas said she was "just voicing her support for Armenians".
Kassab's residents fled after rebels seized their village on March 23, as part of a rebel offensive in the coastal Syrian province of Latakia, Assad's ancestral heartland.
There are no credible reports that rebels killed any residents, or that they inflicted major damage on churches.
Kardashian's Kassab tweets were followed by a flurry of selfies of her riding on a boat in a skimpy top and long skirt with hashtags such as WishYouWereHere and WhatALife.
She has been posting from Thailand, including a picture that shows her sitting at the entry of a temple featuring Buddha.