The victim, 78-year-old Brian Hurry, was found at an address in Bramwoods Road, Chelmsford, on Saturday, Essex Police said.
The arrested woman, aged 41, and the men, aged 24 and 43, all from Chelmsford, are being held in custody.
Investigators are at the scene, which remains cordoned off. A post-mortem examination is yet to take place.
Two men and a woman have been arrested on suspicion of murder after a man was found dead in Essex.