Lipnicki was born in California, the son of Rhonda (née Rosen) and Joseph Lipnicki. He has an older sister, Alexis. Lipnicki is Jewish; his father was born in a refugee camp in Germany, grew up in Montreal, Quebec, Canada, and immigrated to the United States in the 1960s, in response to the events involving the Quebec independence movement.

Lipnicki made his film debut in 1996's Jerry Maguire, the son of Renée Zellweger's character. This is a role for which he has been remembered. He subsequently appeared on The Jeff Foxworthy Show as well as episodes of Dawson's Creek and the 1997 sitcom Meego. In 1999, he starred in the film Stuart Little, playing a boy whose family adopts a talking mouse, a role he reprized in the film's 2002 Read more...

Lipnicki is known for his contributions to charity, having appeared and/or spoken at events for the Breast Cancer Research Foundation, Juvenile Diabetes Research Foundation, Starlight Children's Foundation and NBA's Read to Achieve. He is also the international spokesperson for Pediatric Chiropractic and Kids Day American/International. He was named one of "the heroes of 2001" by JDRF for his involvement. Read more...