The couple exchanged nuptials on Saturday at the Ojai Presbyterian Church in Ojai, near Los Angeles.
Walsh, 39, wore a custom-made Monique Lhuillier dress.
The actress only met 36-year-old Young--a production co-president at 20th Century Fox--in February, and they were engaged three months later.
She told People.com after Young proposed, "I'm literally living the dream. But you know when you know. I was not expecting it, so it's kind of amazing."
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