Waseem Baloch was arrested within days of the murder and confessed on video to killing his 25-year-old sister at her family home in the city of Multan in Pakistan's Punjab province. Despite his admission, he pleaded not guilty in court and in 2019 was sentenced to life imprisonment.
Pakistan's so-called 'honor killings' typically involve the murder of a woman by a relative who believes she has brought shame upon the family. At the time of Qandeel Baloch's murder, Pakistan law allowed a murder victim's family to pardon a convicted killer.
Rights activists feared this law would be used to spare Waseem Baloch.
But Waseem Baloch's acquittal Monday has outraged women's rights activists in Pakistan.
"This is the sorry state of not so sorry State...we are sorry Qandeel. Shocked and speechless," she said.
Sanam Maher, the author of "A Woman Like Her: The Short Life of Qandeel Baloch," also expressed her anger on Instagram.
"In a society that takes great pleasure in the punishment of women who break the rules, it should come as no surprise that each suspect in this case has been acquitted," Maher said.
"After today's verdict, we may ask, who killed her? Nobody, it seems. In accepting that answer, we are all complicit in the crime of failing to protect women."
Qandeel Baloch gained both fame and notoriety in inherently conservative and patriarchal Pakistan for her bold, sassy and increasingly political social media posts.
In posts not dissimilar to the millions of posts and videos shared by 20-something social media celebrities across the Internet, she pouted into the camera, discussed hairstyles and shared cooing confessions about her celebrity crushes.
Qandeel referred to herself as a "modern day feminist" and had nearly 750,000 followers on Facebook.
But in Pakistan, her antics pushed the boundaries of what is considered acceptable.
"I drugged her first, then I killed her," he said. "Girls are born to stay home and follow traditions. My sister never did that."