The names of the 35 women who died in the Barnbow munitions factory explosion near Cross Gates on December 5, 1916, were read out during the service.
Director general and master of the Armouries, Edward Impey, welcomed a packed entrance hall of guests before the roll call of those claimed in the disaster was read out by Jemma Bulmer and Zofia Matyjaszkiewicz.
Mr Impey said: “At the time, this catastrophe was hushed up.
“We can be confident that the women who worked and died in the factory, like the men on the frontline, will be properly remembered.”
He added: “Without these ammunitions the Somme would have been a German victory.
“It was hard and it was dangerous work.”
This year marks the centenary of the end of the Battle of the Somme, which lasted from July 1 to November 18, 1916, and claimed 420,000 British men alone.
Visitors joined the Leeds Philharmonic to sing I Vow To Thee My Country before Archdeacon Arthur Hawes addressed the crowd.
He said: “More people have died in wars in the last century than ever before in the history of mankind and as a consequence it’s even more important to hold them in our memories.”
The last post was performed by a lone bugler and poppies were dropped from floors above on to the ceremony’s guests.
Two minutes of silence were observed at 11am before the audience joined in with the National Anthem at the close of the service.
Carole Smithies, of Barwick-in-Elmet, worked at the Barnbow factory after it started to produce battle tanks following the Second World War.
She retired in 2000 when it was closed and considers herself “one of the last Barnbow lasses”.
“It’s said that without the work that these women did, the United Kingdom could not have won the Great War,” she said.
“I thought the service paid them the respect they are due.”
Twenty six women died instantly in the explosion at the shell-filling factory followed by nine more afterwards, and 30 were injured.