Officers found the 47-year-old at a house in after they were called to reports of a break-in just after 7.30am today (Monday).
-> Radio presenter 'did not see' 20-year-old bike rider before careless collision which killed him in North YorkshireThe man was treated for smoke inhalation - then arrested on suspicion of burglary and arson, said West Yorkshire Police.
A police cordon is in place at the house on Asquith Avenue in Morley as forensic examinations are carried out.
A police spokesman said: "The male suspect had become trapped in the house and had started a fire.
"Emergency services attended the scene.
"The three occupants of the house – two women and a man – were safely out of the property.
"The suspect, a 47-year-old man, from Leeds, was brought out of house by officers and was treated by ambulance staff for smoke inhalation before being taken to hospital as a precaution.
"He was arrested on suspicion of burglary and arson.
"A number of officers who entered the building were checked over by ambulance staff for the effects of inhaling smoke."