The 40-year-old mother of three kids with Ben Affleck - Violet, 7, Seraphina, 3, and Samuel, 10 months - won Today's Parent Magazine's poll by "a landslide", reported ET online.
The magazine listed reasons such as how Garner appears relatable yet still "gorgeous and put-together," and also noted her honesty about being overwhelmed and exhausted as a mother of three.
Juggling motherhood with her acting career, Garner has managed to star in a few well-received movies this year like 'The Odd Life of Timothy Green' and 'Butter', which she also produced. She'll also star opposite Matthew McConaughey in next year's highly anticipated 'Dallas Buyers Club'.
The Celebrity Mother of the Year runner-ups for 2012 include actress Reese Witherspoon, R&B star Beyonce, designer Jessica Simpson and actress Jessica Alba.