The This Means War actress said that she feels "very happy and very lucky" to be with Hollywood agent Jim Toth, who she married in March 2011.
"It's a wonderful time in my life at the moment. I've had trepidations about relationships and getting married again," she told The Mirror.
"I've never wanted fear to be the reason that I didn't find happiness... I'm very happy and very lucky. It just feels right. It's the right thing and he's the right person at the right time in my life.
"It's a great experience to find somebody that you feel well-matched with and that you can build a life with."
Witherspoon, who separated from first husband Ryan Phillippe in 2006 and also dated Jake Gyllenhaal, said that she has no regrets about her romantic past.
"I don't feel bad about any of the things I've done and gone through, whether it's divorce, break-ups or anything like that, because it's all part of life's journey," she declared.
"I'm very good friends with a lot of my exes and I'm even friends on Facebook with the first boy I ever kissed!"
Witherspoon has also said that she would love to have children with Toth.
This Means War is currently playing in the US and will hit UK cinemas on March 2.
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Watch a preview of This Means War below: