Ineta Dzinguviene, 25, is a Lithuanian national.
She was charged over her son's death after his body was allegedly found on Tuesday in a holdall in a block of flats in the Buchan town of Fraserburgh.
The flat where the mother lives in the town's High Street remained cordoned off yesterday.
Forensic officers were seen carrying out an examination of the scene.
Police launched a major investigation, setting up road blocks across the north-east town yesterday afternoon.
Motorists were stopped and shown posters with Miss Dzinguviene's name and picture on it.
The infant is understood to have been only a day old when he died.
A police spokesman said: "In respect of the ongoing inquiry in Fraserburgh into the death of a baby boy, police can confirm that a 25-year-old woman has been charged with murder.
"She is expected to appear at Peterhead Sheriff Court on Thursday."