The attack took place at the apartment in Hässelby, a suburb in western Stockholm, at 8pm on Saturday. The woman, who was in her thirties, received knife injuries to the abdomen. She was taken to Karolinska University Hospital, where she died later during the night.
The man, aged 45, was later arrested on suspicion of murder.
“We have held a short interview with him, and he has been informed that he is suspected of murder,” said Bengt Kihlberg of Stockholm Police.
Police are currently releasing few details about the circumstances of the killing, but Kihlberg said that the man and his alleged victim have a two-year-old child together.