The Scottish Fire and Rescue Service (SFRS) was called to a fire affecting several properties at George IV Bridge in Edinburgh at 6.18am on Tuesday.
The firefighter was released from hospital later that morning after undergoing precautionary checks, while one other person was treated at the scene.
Images from the area early on Tuesday showed smoke pouring from a branch of Patisserie Valerie, next door to the Elephant House cafe, which was made famous as the place where JK Rowling wrote part of the Harry Potter series.
Some road closures are still in place in the area, but the cordon has now been reduced to allow pedestrian access to all premises north of the bridge over Merchant Street
Candlemaker Row, Merchant Street and the remainder of George IV Bridge still remain closed.
The Fire Service has stood down but a Police presence will remain, along with contractors.
In a statement released on Wednesday evening, Depute Council Leader Cammy Day said: “Thankfully no one was seriously injured, though our thoughts are with the fire fighter who received hospital treatment.
"We also sympathise with the building owners who will now have to deal with the repercussions of this fire.
"Our Shared Repairs Service will remain on-site, along with contractors, to assess the damage and make the area safe.”
Council Leader Adam McVey added: “Thanks to the swift response of all partner agencies involved we’re now able to begin gradually reopening George IV Bridge – once again they have served our Capital with distinction.
"As the recovery and further investigations continue, there will still be some disruption to traffic, as well as bus diversions.
"We’re working to keep this to a minimum, in close communication with Lothian Buses, though I would encourage anyone travelling to the area to check the latest diversion information.
“It’s down to the tireless work of the Scottish Fire and Rescue Service that this major fire was brought under control. while our Resilience and Roads teams, along with Police Scotland, were quick to make the surrounding area secure yesterday.
"They were greatly aided by the Salvation Army, who kindly provided tea and biscuits to all those helping out!”