Traders and workers at the City of London Corporation's Smithfield Market, including some who witnessed the fire, which raged for four days 50 years ago, gathered at the service with more than 20 officers from the Fire Brigade.
Superintendent of the Smithfield Market Robert Wilson said: "We are gathered here today to honour and remember the bravery of Station Officer Jack Fourt-Wells and Fire Officer Richard Stocking and the fact that they fearlessly gave their lives to save others.
"We acknowledge their sacrifice and salute all Fire Brigade officers involved in this tragic event."
Smithfield Market Tenants' Association Deputy Chairman, Mark Twogood said: "The dedication shown by all those firemen involved in fighting the fire in this Market in 1958 epitomises the service which Londoners know the Fire Brigade is ready to deliver every day."
Deputy Commissioner of the Fire Brigade Roy Bishop said: "This is a landmark fire in the history of London and its Fire Brigade. It is important that we remember this tragic fire and honour the memory of the two London fire-fighters who lost their lives."
Valuable lessons were learnt from the tragic Poultry Market fire. A tally system was introduced as a result which meant that a record was kept of exactly where the fire officers were and the time they went into the building so that the co-ordinator could recall them when their oxygen ran low and, in the event of a problem, knew where to locate the officer. These procedures were tested to the limit at the Kings Cross fire in 1987.