In recent days a number of incidents have occurred including significant damage to the trees in Erganagh and Castlederg where lights were torn down and the hoarding was pulled off the tree and a flower bed was vandalised.
In Guildhall Square the large bauble, which has proved popular with the public for photographs, was vandalised at the weekend and extensive damage was caused to the reindeer at the start of this week.
Head of Environment at Council, Conor Canning, appealed to those responsible to consider the impact of their reckless actions.
"Despite numerous appeals, our Electrical and Maintenance teams are unfortunately still dealing with vandalism to the Christmas decorations across the City and District on a daily basis," he said.
"As well as the obvious dangers, this is costly and time consuming for our teams and represents criminal damage.
"The PSNI, Community Safety Wardens and CCTV operators are keeping a close eye on Guildhall Square and Waterloo Place in particular.
"The decorations are there for everyone in the community to enjoy so we would appreciate if people respect them and report any incidents of vandalism you experience to the PSNI," he added.