The woman, who is in her 60s, was injured in a fire at a semi-detached house in Penderel Street, Bloxwich, at about 10.45am on Wednesday and taken to Queen Elizabeth Hospital in Birmingham.
The fire was confined to one downstairs room and was out when firefighters arrived. Burnt furniture including blackened sofas were left outside the house.
Interactive map of the area:
Watch commander Colin Ward said: "We were called at 10.30am and sent three fire appliances.
"We rescued a lady who has gone to hospital with quite serious burns.
"The fire was already out on our arrival.
"The cause of the fire is currently being investigated by police and fire service.
"Unfortunately a dog died."
One neighbour, who wished not to be named, called the fire "devastating", adding: "It was shocking to see, devastating. It has never happened on the street before."
Jamie Arrowsmith, spokesman for West Midlands Ambulance Service, said: "At 10.29am we were called to reports of a fire at a property in Penderel Street.
"We sent one ambulance and a paramedic officer to the scene.
"We have treated one patient, a woman in her 60s, for serious injuries.
"She was taken to the QE Hospital for further treatment."
West Midlands Fire Service and West Midlands Police have been contacted for comment.