Tracie Castleton is calling for help in reuniting her daughter Amelia with the "memory bear" which was a reminder of her dad who died in April and was lost in London over the New Year.
The Rotherham mum wrote: "I know it's a long shot but please please share!
"My little girl lost her daddy in April and the bear is her comfort in his memory. She is devastated and inconsolable.
"My daughter feels like she has lost her daddy all over again. Please help find him. He isn't worth anything financially but he is priceless to my daughter. Thank you."
The bear was last seen at the Comfort Inn Hotel in King's Cross on New Year's Eve.
She added: "The hotel say they have checked the room but have not found him and have given up looking for him.
"He never left the room with us 100%. My only thought is that he got bundled up in the bedding when the cleaners cleaned the room on our departure.
"If anyone does come across him please let me know."
The bear is a light brown Build a Bear teddy wearing blue checked shirt and denim jeans. He has a heartbeat when squeezed and when you squeeze his paw he has a recorded message that says " I love you dad from Amelia."