Fire crews from Sleaford and Billingborough were called to a house on Redwood Avenue in Sleaford at about 8.20am, according to the fire service.
The utility room and contents were damaged by the fire which is believed to have started from a fault with a tumble dryer.
A Lincolnshire Fire and Rescue Service spokesman said: “Sadly one cat was found deceased.”
There was smoke and heat damage to the remainder of the property. The fire was put out by firefighters wearing breathing apparatus using a hosereel and main jet.