Family
- father Frank Muniz: Born c. 1956; divorced from Muniz's mother; lived in North Carolina
- mother Denise Muniz: Born c. 1955; divorced from Muniz's father; moved to California to oversee son's career
- sister Christina Muniz: Born c. 1984
Companions
- Hilary Duff: born on September 28, 1987; Muniz claims they are "very, very close ... we're like a couple ... we don't say we are"
- Megan Hubbell: born c. 1986; no longer together as of March 2003
- Companion Jamie: Met in New Orleans, while he was filming "Stay Alive" (2006); engaged from 2005-2007; no longer together
