USA Cycling said the Olympic medalist, who won silver at the Rio Games, has passed away and paid tribute to her in a statement.
Catlin claimed glory in the team pursuit at three successive world championships on the track between 2016 and 2018.
She also won individual pursuit bronze at the 2017 and 2018 championships.
Catlin's brother Colin confirmed his sister had taken her own life.
"My sister Kelly committed suicide last night," he wrote on Facebook.
Catlin won all three of her world titles alongside Chloe Dygert Owen and Jennifer Valente.
Kimberley Geist was part of the team in 2017 and 2018, while Sarah Hammer rode in the 2016 triumph.
"We are deeply saddened by Kelly's passing," said USA Cycling president and chief executive Rob DeMartini.
"We will all miss her dearly. Kelly was more than an athlete to us and she will always be part of the USA Cycling family.
"Our thoughts and prayers are with the Catlin family. This is an incredibly difficult time and we want to respect their privacy.