Chelsea, 15, was last seen in Eastbourne on Wednesday, May 28, police added.
A spokesperson for Sussex Police said: “She is described as 5’ tall and having blonde hair. She was last seen wearing a fluffy pink coat and a pink tracksuit.
"Chelsea is known to have links to Brighton, Worthing, Bournemouth and Portsmouth. If you see her or know where she is, please call 101 quoting serial 1488 of 28/05.”
1. Chelsea, 15
Chelsea, 15 Photo: Sussex Police