user: The cat, named Phoenix by rescuers, had severe burns to her face and body after being spotted trapped under blazing rubble in Sunderland in June.
She has been cared for by RSPCA staff at Felledge, near Chester-le-Street and is expected to make a full recovery.
Phoenix, now 14 weeks old, still needs daily treatments but is now playing with other kittens, centre staff said.
No-one knows how she came to be trapped in the fire or if she had a previous owner.
Luka Atkinson, reception supervisor at RSPCA Felledge, said Phoenix was in a "really sorry state" when she arrived.
"The skin on all four of her pads was burnt off and the fur on her face, tummy and legs was singed - she was lucky to be alive," he added.
"It's definitely been tough seeing Phoenix go through her recovery and she's not out of the woods yet, but the whole time we have had her here she has been eating really well, drinking, and has loved cuddles and playing, so we knew we had to keep going with her treatment and give her a chance.
"She is such a happy little thing and runs riots with the other kittens at our centre... She really is the luckiest kitten in Britain."

Sum: A kitten - dubbed Britain's luckiest - is recovering after being rescued from a garden fire.


Eight-year-old Findlay Watters found the half-metre-long blade near an earth mound beside a Kirkwall campsite.
It is not yet know how old the object could be.
Findlay's mother Helen Sutherland has contacted Orkney Museum for help.  One local historian said the item looked African in origin.
Christopher Gee said it could possibly be a Ngbandi short sword which might be over 100 years old.

Sum: The discovery of a rusty sword-like object by a schoolboy in Orkney is being investigated by experts.


"Rodgers out, Rafa in", read the message in a stunt organised by a campaign group called RodgersOutClub.
Rodgers, appointed in May 2012, is the first Liverpool manager in more than half a century not to win a trophy in his first three seasons at the club.
Many fans and former players including Jamie Carragher condemned the banner.
Earlier on Saturday, Carragher tweeted: "About to leave for Anfield. Hope this Rodgers banner supposedly flying over the ground is called off as it's embarrassing to club and fans."
Rodgers, 42, who took the Reds to the brink of the Premier League title last season only to lose out to Manchester City, believes he is still the right man to take the club forward.
He said: "I thought it was Rafa's agent.
"Football has short memories. We sat here last year and nearly won the league."
He also insists the club's American owners, Fenway Sports Group, will support him with marquee signings this summer.
Former Reds manager Rafa Benitez, who led the club to Champions League success in 2005, is expected to leave Serie A side Napoli at the end of the season.

Sum: A plane trailing a banner calling for Brendan Rodgers' dismissal flew over Anfield before Liverpool's game with QPR.


The firm said it was looking for a range of staff including software developers and warehouse staff.
There will be jobs at Amazon's head office in London, as well as in the Edinburgh customer service centre and in three new warehouses.
The recruitment will take Amazon's workforce in the UK to more than 24,000.
Doug Gurr, the head of Amazon's UK business, said: "We are creating thousands of new UK jobs including hundreds of apprenticeship opportunities as we continue to innovate for our customers and provide them with even faster delivery, more selection and better value."
The company is opening three new warehouses, or what it calls "fulfilment centres", in Tilbury, Doncaster and Daventry.
The extra warehouse space will be used to cope with existing growth and to speed-up deliveries.
It will also handle deliveries for third-party retailers, who sell through Amazon's website and use Amazon for deliveries.
Growth in those third-party sellers has been particularly rapid.
The expansion reflects the importance of the UK market, which is Amazon's second biggest outside the US, behind Germany.
Services which are developed in the US are usually launched in the UK first, such as Amazon Fresh, the grocery service which was launched in parts of the UK last summer.
As well as expanding in groceries, Amazon is also pushing into fashion, says Natalie Berg, retail analyst at Planet Retail.
Clothes sales are already one of its fastest growing areas and it has been reported that Amazon is close to launching its own-brand fashion label.
That rumour has been fuelled by Amazon's creation of a fashion photography studio in London's Shoreditch.
"If you are a grocer or fashion retailer, Amazon is keeping you up at night," said Ms Berg.
Last year Amazon had to defend its employment practices after a BBC reporter, working undercover at an agency which was contracted by Amazon to deliver parcels, spoke to drivers who claimed they worked illegally long hours and were expected to deliver up to 200 parcels a day.
Amazon said it was committed to ensuring drivers drive safely and legally, and are "fairly compensated".

Sum:

assistant: Online retail giant Amazon has said it will create 5,000 new full-time jobs in the UK this year.