The Keeping Up With The Kardashians star - formerly known as Bruce Jenner - told Vanity Fair magazine that she spent around two years thinking about the perfect name and it was only when her assistant also suggested Caitlyn that she made her choice.
"It's one of the hardest things in life - choosing your own name," she admitted.
After mulling over Heather and Cathy, she settled on Caitlyn after assistant Rhonda independently suggested it as an option. Caitlyn had already placed the name on her maybe list beforehand.
As for why she didn't follow the Kardashian-Jenner tradition and spell Caitlyn with a K, the former athlete admitted she did consider but but wanted to break with the tradition and have a fresh start.
Caitlyn, 65, will make her public debut as a woman at the ESPY Awards on 15 July, where she'll be honoured with the Arthur Ashe prize for courage.
"In the past few months, the overwhelming outpouring of support from all over the world for my journey has been incredible. However, being honoured with this award, which is named after one of my heroes, is truly special. For the first time this July, I will be able to stand as my true self in front of my peers."
Caitlyn will attend the ceremony with members of her famous family, though it has not yet been confirmed which members that will be.
She has children Kylie, 17, and Kendall, 19, from her marriage to Kris Jenner, as well as stepchildren Kim, Kourtney, Rob and Khloe. She's also got kids Bruce, Cassandra, Brody and Burt from previous marriages.
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