The four Iraqi civilians brought claims that they had been unlawfully imprisoned and suffered ill-treatment by British troops between 2003 and 2007.
The ruling could pave the way for the settlement of a further 600 unresolved claims against the Ministry of Defence, in what is known as the Iraqi Civilian Litigation.
Abd Al-Waheed was arrested in a house raid carried out by British soldiers in the city of Basra in February 2007. He was awarded £33,000.
Kamil Najim Alseran was captured by British troops in Basra in March 2003, and was awarded £10,000 for mistreatment after his capture, and another £2,700 for 27 days of unlawful detention.
Two other men can only be referred to as MRE and KSU for legal reasons.
They were serving on a merchant ship at the beginning of the war, which was boarded by coalition forces in March 2003. They, and two other crew members, were captured.
MRE was awarded £28,140, which was made up of £10,000 for 'hooding' (where sandbags are used to cover a person's head) during the road journey, £1,000 for an eye injury he sustained during that time, and £15,000 for a blow to his head.
There was also an award of £1,440 for medical treatment and £600 for six days of unlawful imprisonment.
KSU also received £10,000 for hooding, and a further £600 for the same period of unlawful detention.
The two High Court trials were the first in which Iraqi citizens gave evidence in an English courtroom.
Mr Justice Leggatt said: "Four cases have been tried as lead cases. There is no assumption that these four cases are representative of others, but the conclusions reached on the legal issues and some of the factual issues raised are likely to affect many of the remaining cases in the litigation."
An MoD spokesman said: "Our military personnel served with great courage in Iraq, often working under extremely difficult circumstances.
"We note the court's ruling that these four detainees were not treated as they should have been, and are studying the judgment."
Sapna Malik, a partner in the international claims team at Leigh Day, who represented Mr Alseran and Mr Al-Waheed, said: "Our clients are grateful that the judge approached their claims without any preconception or presumption that allegations of misconduct by British soldiers are inherently unlikely to be true.
"Our clients' evidence has been tested at length in court and the Ministry of Defence has been found wanting.
"It is vital that those wronged by the UK Government, whether in this country or overseas, are able to seek justice and redress.
"Their ability to do so in our courts is not a witch-hunt but a testament to the strength of our democracy."