- Jessica Marie Alba was born on 28 April 1981, in Pomona, California to Catherine (Jensen) and Mark David Alba, who served in the US Air Force.
- Her father's family is Mexican, while her mother has Danish, Welsh, German, English, Scottish, Scots-Irish (Northern Irish), and French ancestry. A DNA test taken on the television series Finding Your Roots with Henry Louis Gates, Jr. (2012) described Jessica as being of 72.7% European, 22.5% Native (Indigenous Mexican, including Mayan), 2% Sub-Saharan African, 0.3% Middle Eastern/North African, and 0.1% South Asian, ancestry, with an additional 2.4% for which there was no match. Her father's direct matrilineal line was also traced to distant Sephardi Jewish ancestry.
- Has a tattoo of a daisy with a ladybug on it on the back of her neck.
- Her second cousin is skateboarding legend Steve Alba (aka "Salba").
- As a child, she was diagnosed with asthma and ADHD. She still takes Ritalin for her ADHD as an adult.
- Has two pug dogs, named Nancy and Sid.
- Loves to cook. Her specialty is chicken enchiladas and homemade tortillas.
- Loves Harley Davidson motorcycles.
- She has the Sankskrit word for "lotus" tattooed on the inside of her wrist.
- Gave birth to her 1st child at age 27, a daughter named Honor Marie Warren on 7 June 2008. Child's father is her husband, Cash Warren.
- Gave birth to her 2nd child at age 30, a daughter named Haven Garner Warren on 13 August 2011. Child's father is her husband, Cash Warren.
- Co-founder, with Christopher Gavigan, of "The Honest Company", which makes chemical-free products, like diapers.