Graffiti has been daubed across the climate stripes mural on the Waterfront.
The damage was caused sometime overnight on Christmas Day into Boxing Day.
Orange spray paint has been used to deface the mural which was created by Jersey artist Ian Rolls.
Messages on stencil and freehand have been graffitied across the artwork.
It includes the words ‘How dare u scare kids’.
Jersey Police say anyone with information about who did it should call 612612 or Crimestoppers
Jersey Development Company says it is ‘absolutely shocked and very disappointed’ by the vandalism.

"Tropical nights" forecast for the Channel Islands
Les Amis nursing home on track to open this autumn
Candle-lit evening at St Brelade's Bay Beach to remember loved ones
How to have 'safe and enjoyable' Jersey beaches for summer
Appeal after woman grabbed by throat in nightclub
Essential work to begin on Springfield Stadium
Man who dug up cocaine in woods is jailed
Jersey and Guernsey included in UK-Gulf trade deal