Authorities have seen an increase in the number of items having to be confiscated in searches.
These can include small multi-tools with a locking blade, or small knives used in camping or for outdoor activities, where the blade locks.
Meanwhile items that may be legal in other countries are not legal to possess in the UK, such as incapacitant sprays or pepper spray.
Possessing these items is an offence that could lead to a criminal conviction and to the item being confiscated and destroyed.
Passengers should check their bags before travelling to the airport to avoid bringing any prohibited items into the airport itself.
Chief Inspector Chris Veale said: “We are regularly seeing passengers in possession of items that could constitute an offence in the UK.
“All passengers using Gatwick Airport are reminded of the need to check their bags and cases for any items that may be prohibited.
“This is especially relevant where some bags may not have used for air travel since before the pandemic, or people are using bags used at work, where such items may be required for their occupation.
“UK legislation is very clear that the public should not be in possession of items classified as offensive weapons and bladed articles, in particular any item that has a locking blade of any description, this includes multi-tools and knives used for camping or outdoor activities.
“Travelling passengers from overseas should ensure that any items that may be legal elsewhere in the world, such as pepper or incapacitant sprays, are not brought to the airport for return travel. Possession of these items will constitute an offence and may result in a criminal conviction as well as confiscation and destruction of the item.
“If people are uncertain about what can and cannot be taken through the airport they can contact their airline when booking and checking in or check the airport website.”