Camila, 30, gave birth to a baby girl on Friday morning (28 December 2012) at a hospital in Austin, Texas, reports US Weekly.
McConaughey, 43, first announced the news his partner was pregnant in a tweet back in July - a month after he and Alves wed in Texas.
The couple, who have been dating since 2006, already already have two kids, Levi, four, and two-year-old Vida.
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