Children as young as eight years old are spending the equivalent of 61 days a year online.
CyberSafeIreland says nearly all children (92%) they surveyed have their own smart device.
Nearly half, or 43%, of eight to 13-year-olds are talking to strangers online, mostly through social media and games.
CyberSafeIreland chief executive Alex Cooney says the vast majority of children own a device that connects to the Internet:
Ms Cooney said: "Those that owned their own smart device, there were 62% on social media, those that didn't it was 24%, so there is an argument to say that it is worth holding off giving a child their own smart device as that creates a level of independence and ownership.
Minister of State for Higher Education, Mary Mitchell O’Connor, said parents need to supervise their children when they are using smart devices.
She said: "You just have to be able to lock down the phones, there are very good apps out there, you have to make sure that you supervise your children and ensure their safety because that is a parent's responsibility and we will do our part as well."