The 18-year-old star believes marriage should be sacred and private, rather than a desperate bid for media exposure.
But Duff, who is currently dating Good Charlotte rocker Joel Madden, admits to enjoying reality shows such as NEWLYWEDS (starring Simpson and husband Nick Lachey) and Spear's venture with Kevin Federline, CHAOTIC.
She says, "There's this trend in Hollywood for people to get married so young. I really don't know what it's about, whether it's wanting a ring on your finger or just getting in the press.
"I'm definitely not planning on anything like that anytime soon. And if I did, I would not make a huge thing about it.
"Joel is here in the UK with me and we bought video cameras so we were joking around, acting like we were on Newlyweds.
"I can't say I don't like shows like that because I find them so entertaining. I like them, they are so stupid they are funny."