Rhys Hancock, 39, of Portland Street, Etwall, will appear at Southern Derbyshire Magistrates Court on Friday in connection with the deaths of Helen Hancock, 39, from Duffield, and Martin Griffiths, 48, from Derby.
They were pronounced dead at a property in New Zealand Lane, Duffield, in the early hours of Wednesday.
The murder suspect was arrested at the scene of the incident, and Derbyshire Police have revealed that Mrs Hancock had contacted them prior to the incident.
The force, which released the first pictures of the victims on Thursday, said it had therefore referred itself to the Independent Office for Police Conduct.
Officers remain at the house and continue door-to-door enquiries.
Chief Superintendent Hayley Barnett added: “The thoughts of everyone at Derbyshire Constabulary are with the family and friends of Mrs Hancock and Mr Griffiths.
“Our thoughts are also with the Duffield community, which is understandably shocked by this incident.”
Paying tribute to Mrs Hancock, who went by her maiden name of Almey on Facebook, her “devastated” family said they had lost a “lovely, beautiful, friendly, bubbly, and sociable person”.
Mrs Hancock had reportedly been dating Mr Griffiths for six months.
Mr Griffith’s family described him as a “lovely dad, husband, son, brother and uncle, who had a passion for adventure, running and a love of animals”.
They added: “He enjoyed travelling the world, mountain climbing and spending time with his two children. He will be greatly missed.”