The 24-year-old welcomed her second child in February with rapper Travis Scott and at the time announced that they had named the little one 'Wolf'.
However, the beauty mogul later revealed the pair had changed his name as they felt it didn't 'feel like him'.
Now many of her social media followers are convinced Kylie has subtly announced her son’s new name in a video montage journeying her pregnancy and the early stages of her motherhood.
She captioned the tribute post: "Every day should be Mother’s Day. Thank you God for my two beautiful blessings."
However, it wasn’t what was in the video but the accompanying audio, 'To Our Daughter (Lullaby)' by My Best Friend Jacob, that caused a stir.
Now many believe the track was a hint to their son’s name with internet sleuths convinced it's Jacob.
Taking to Reddit, one penned: "Could the baby's name be Jacob?”
While another commented: "Kylie's baby is named Jacob and I'm 99.9% sure of this."
"Kid's called Jacob,” a third wrote.
Aside from guessing her son’s name, fans were given a look at the first ever photo taken of him in the heartfelt post.
Taking to Instagram on Monday, the Keeping Up with the Kardashians star uploaded the short video paying tribute to her two children for a Mother's Day post.
From showing footage of the first-ever ultrasound scans of her son, an intimate shot of showing her pregnant belly moving, some artsy silhouette shots from a pregnancy photoshoot all the way through to the final clip that made her fans’ hearts’ melt.
The end clip showed Kylie holding out her hand to her newborn son, as he adorably gripped onto one of her fingers with his miniature little fist.
"OMG so cute," commented one fan.
A second wrote, "Aw, what a cute baby."
"God bless this beautiful family," a third said.