Relatives of soldiers killed in Iraq have been fighting to sue the Ministry of Defence for negligence and make claims under human rights legislation.
The Supreme Court justices have announced that they will be able to do both.
Families started legal action as a result of the deaths of a number of British soldiers following the American-led invasion of Iraq in 2003.
Their victory at the UK's highest court follows a hearing in London in February.
The decision means that claims can now proceed to trial.