"14 yrs ago 2day @AmericanIdol opened a door w/such amazing opportunities & experiences 4 me! I am 4ever grateful & blessed! #heresto14more," the singer tweeted Sunday.
Clarkson, now 34, was the winner of the first season of the singing competition series in 2002.
She has gone on to have a successful music career with hit songs such as "Miss Independent," "My Life Would Suck Without You," "Stronger [What Doesn't Kill You,]" "Piece by Piece" and "Heartbeat Song."
Copyright 2016 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.