IMDb.com : Margaret O'Brien
- Basic facts, a complete filmography, photo gallery, awards and titles for sale.
- http://us.imdb.com/name/nm0639684/

ReelClassics : Margaret O'Brien
- Illustrated biography of the actress on three pages plus filmography, awards, news and bibliography.
- http://www.reelclassics.com/Actresses/O'Brien/obrien.htm

WIC Biography : Margaret O'Brien
- A short biography of the famous child star of 1940s.
- http://www.wic.org/bio/mobrien.htm

Class Act : Margaret O'Brien
- Brief biography, complete filmography with movie reviews, photos and a link to her autobiography.
- http://www.classicmoviemusicals.com/obrienm.htm