"Why is he the right person for me? All I know is that I feel completely seen, and adored, in no matter what state," Aniston told the magazine.
"There's no part of me that I don't feel comfortable showing, exposing. And it brings forth the best part of myself, because I care about him so much. And he's such a good person. It hurts me to think of anyone hurting him," she said.
Aniston and Theroux married in August 2015 after more than four years of dating. The actress, who was previously wed to Brad Pitt from 2000 to 2005, denied she and Theroux are expecting in an op-ed for The Huffington Post in July.
"My marital status has been shamed; my divorce status was shamed; my lack of a mate had been shamed, my nipples have been shamed," she said of the piece in Marie Claire. "I just thought: I have worked too hard in this life and this career to be whittled down to a sad, childless human."
Theroux told Entertainment Tonight in September that his marriage to Aniston works because they complement each other well. The couple co-starred in the 2012 movie Wanderlust and would "love" to work together again.
"We appreciate each other's sense of humor, we respect one another and we get along," the actor said. "I know it sounds simple but it's true!"
"We would love to [collaborate again]," he added. "I've been working for the last three years on [The Leftovers], which sort of prevents me from working on anything else. And it has to be the right thing and something we both want to do."
Aniston will next star with Jason Bateman and Olivia Munn in Office Christmas Party, which opens in theaters Dec. 9. Theroux plays Kevin Garney, Jr., on The Leftovers, which will return for a third and final season on HBO in 2017.