Dozens of the letters to the 33-year-old were released by prosecutors.
“In my heart I know you are a great guy,” wrote a woman named Candace. "If you do write me back I’d be the happiest girl alive that's for sure."
She signed off with hashtags #TeamChris, #ChrisIsInnocent, #LoveHim and #SooooCute.
Another woman, named Tatiana, wrote, “I find myself thinking a lot about you” and sent a photo of herself in a bikini.
“I’m hoping to brighten your days,” wrote another woman named Kim.
A woman named Hannah wrote: “I feel this connection to you.”
Psychologist Dr. Judy Ho, co-host of "Face the Truth," says even the worst killers like Chris Watts have groupies who write to them, visit them, and even propose marriage.
“These women have created a fantasy life for themselves especially with their pretend relationship with these men behind bars,” she told Inside Edition.
“It is oftentimes what we talk about when women seem to be attracted by bad boys. It is because they want to be the special person that can turn this life around and be able to attribute that to their own self esteem," she said.
Other famous inmates including Nikolas Cruz, who is accused of carrying out the Parkland School massacre, Boston Marathon bomber Dzhokhar Tsarnaev, and Scott Peterson, who is on death row for murdering his wife and unborn child, have all reportedly received love letters from women.
Watts, from Colorado, was sentenced in November to three consecutive life sentences for killing his pregnant wife, Shan'ann, and their two daughters, 4-year-old Bella and 3-year-old Celeste, in mid-August.
He also received two more life sentences to be served concurrently, 12 years each for three counts of tampering with a deceased body, as well as 48 years for unlawful termination of a pregnancy for the death of his unborn child.