Kylie Jenner has stepped in to help the family of her hairstylist who died unexpectedly over the weekend -- paying funeral costs and other expenses ... TMZ has learned.

Sources with direct knowledge tell TMZ ... Kylie has been privately working with Jesus Guerrero's family to transport his body back to his hometown of Houston and pay for the funeral.

Our sources tell us Kylie first learned of Jesus' death early Saturday morning ... and on Sunday she spent much of the day with his family comforting them and offering to help them however she could.

Jesus first started working with Kylie in 2019 and the two became best friends over the years, sharing several photos together on social media. Jesus also worked with Hollywood A-listers like Jennifer Lopez and Katy Perry.

Jesus died suddenly and unexpectedly over the weekend, according to a GoFundMe post by his sister.

Kim and Khloe Kardashian shared tributes to Jesus on Monday. Kim shared on her Instagram Story that her heart was breaking for her grieving sister, emphasizing in their world, the "glam squad" becomes family -- so Jesus' passing hit especially hard.

Khloe shared similar words, saying their family spends a lot of time with their glam teams, and called Jesus' death an incredibly deep loss.

Jesus' cause of death has yet to be revealed.