Prime Minister Gordon Brown, lawmakers, and officers looked on as the queen toured the Armed Forces Memorial, set in the National Forest in Staffordshire, about 130 miles (200 kilometers) northwest of London.
The memorial honors not only those slain in battle - a small minority among the 16,000 names on the monument's walls - but all those killed in training, exercises or operations. Military victims of terrorism are also included, and the queen paused to examine the name of her cousin, Earl Mountbatten, who was killed by an IRA bomb in 1979.
In his dedicatory sermon, the Archbishop of Canterbury Rowan Williams said the monument was about "naming all those who have been ready to risk everything for the good of our national community, and indeed the good of our world.
"Some of them have died in heroic circumstances, some in tragedy and conflict, some in routine duties - but all of them as parts of a single great and generous enterprise."
British military officials have complained that memorials to those killed in the dozens of conflicts involving British troops since World War II either did not exist or were too remote for most families to come and pay their respects.
The 6 million pound (US$12 million, €8.6 million) memorial, built atop a large mound, was designed by architect Liam O'Connor. Inside are two straight stone walls, which frame bronze sculptures by Ian Rank-Broadley.
Those killed in Palestine, Korea, Malaysia, the Falklands, Iraq, Afghanistan and Northern Ireland, and while on duty in peacetime are among those commemorated.
The memorial, which is due to open to visitors later this month, still has space left for 15,000 more names.
The choice of the city of Helsinki is not incidental as the capital of Finland had hosted US-Soviet negotiations on the limitation of nuclear stockpiles in 1969