The researchers, commissioned by Scots charities, examined 74 studies done across the world in the past decade.
They concluded that smacking was associated with increased childhood aggression and antisocial behaviour.
There was also a "worrying risk" of escalation into physical abuse.
The report was commissioned by leading children's charities in Scotland, as well as the country's Children's Commissioner, and compiled by academics at University College London.
It found that in many countries, including the UK, the use of physical punishment was declining - although the decline had been quicker in many of the 47 countries that have already outlawed smacking.
It also found that public attitudes had shifted, with the use of physical punishment becoming less and less acceptable and a high proportion of parents doubting its usefulness.
But it said physical punishment was still common in Scotland and the UK, despite its negative effects being known and the fact that it "constitutes a clear violation of children's human rights".
Among the key findings of the report were:
The report concluded: "The evidence for harmful effects of physical punishment is strong and consistent, and the declines in the use of physical punishment in countries where it is prohibited make a compelling case for the introduction of such legislation.
"The current laws across the UK allowing physical punishment of children in the home and in private foster care should be challenged from both a human rights and a child wellbeing perspective.
"The international human rights consensus on physical punishment is clear: repeated examinations of UK laws have stated in unequivocal terms the imperative of legal reform to protect all children against all forms of physical punishment in all settings."
Earlier this year, a United Nations report called on the UK to "put an end to corporal punishment in all settings" and encourage non-violent forms of discipline instead.
Parents in England and Wales are currently allowed to use "reasonable chastisement", although criminal charges can result from any punishment that leaves a mark such as bruising, swelling, cuts or scratches.
In Scotland, it is illegal to hit children on the head, shake them or punish them with a belt, cane of other implement.
Both the Scottish and UK governments have said they do not wish to criminalise parents who "lightly" smack their children. A bid to outlaw smacking in Wales was rejected by the Welsh Assembly last month.
The researchers said that this position "contradicts the evidence base that physical punishment carries a serious risk of escalation into injurious abuse".

The app samples wireless signals to see if data is flowing uninterrupted from routers to phones and tablets.
The app is released alongside research which suggests wi-fi in six million homes and offices is not running as fast as it could do.
The app also provides tips to help people spot what might be slowing down their wi-fi speed.
Interference could come from other electronic devices such as baby monitors, microwaves or Christmas fairy lights, said Ofcom in a statement.
Statistics about home wi-fi speeds are in Ofcom's 2015 Connected Nations report that looks at the state of telecoms and wireless networks in the UK.
The report said there had been "good progress" on the availability and use of telecoms services. About 27% of UK homes now have super-fast broadband that runs at speeds in excess of 30 Megabits per second (Mbps). Last year the figure was 21%.
Super-fast broadband is now available to more than 83% of UK homes - up from 75% in the same period in 2014.
The research also found that those with the higher speed connections to the net are doing more with them. People with faster connections were now making significant use of catch-up TV services, online film rental services and video calls, it said.
Much of the UK's appetite for data was being driven by households that have the super-fast services, said Ofcom.
However, despite the growing use of high-speed broadband it also acknowledged there was "still more to do".
The research found that 2.4 million UK homes, about 8%, cannot get speeds of 10Mbps or more. Many of these homes were in rural areas.
It also said broadband speeds needed to increase for those on the move and said small businesses were being particularly poorly served when it came to access to services of 10Mbps or more. About half of all small or medium-sized firms based in business parks do not have access to net links of such speeds.
Academics have called for a ban on smacking after finding "compelling" evidence that it creates a "vicious circle" of conflict and violence that carries on into adulthood.
[NEXT_CONCEPT]
Christmas tree lights can slow your wi-fi warns watchdog Ofcom as it releases an app that can check home broadband.