Princess Margaret was born at Glamis Castle in Scotland, making her the first member of the royal family in direct line of succession to be born in Scotland since the 1600s. Her birth was a significant event, with the Home Secretary, J. R. Clynes, present to verify it. The registration of her birth was delayed to avoid her being numbered thirteen in the parish register.

Margaret was baptized in the private chapel of Buckingham Palace by Cosmo Lang, the Archbishop of Canterbury. This marked an important religious milestone in her early life.