The bodies of Tracy and Louise Donnelly were found at an address on Ironside Road, Sheffield, on Tuesday.
Police said a post-mortem examination revealed both women died from multiple stab injuries.
A four-year-old boy who was inside the property at the time of the incident was unhurt.
Rekawt Mahmood Salih, of Callow Mount, Gleadless Valley, was arrested after the bodies of the two women were discovered and has now been charged with two counts of murder.
Salih is due to appear at Sheffield Magistrates’ Court today