South Wales Police said a 30-year-old man had been bailed to appear before magistrates in the city on 14 January.
Emergency services were called to a house in the Fforestfach area on Friday morning and the baby was taken to hospital where he was pronounced dead.
A pathologist has carried out a post mortem examination and police inquiries are continuing.
What are these?
Most Popular Now | 136,614 people are reading stories on the site right now.
Bookmark with:
What are these?