In her new role, she'll focus on women's issues, NBC said in a statement Tuesday, including the "shifting roles, emerging power and evolving needs of women in modern life."
Her reports will also appear on NBC News cable channels CNBC and MSNBC and on NBC Sports, the network said.
She'll also serve as editor-at-large for women's issue across NBC News digital properties.
Shriver, 57, broke the news of her new role on Twitter and then posted a piece about it on LinkedIn.
"I'm excited to be going forward with @NBCNews as a special anchor," she said on Twitter.
"I will also be profiling people I like to call 'Architects of Change,'" she wrote on LinkedIn, defining the architects as "groundbreaking women and men who are pushing the boundaries of society, technology, media, science, business, faith and politics."
The Kennedy family member, who will be based in Los Angeles for the program, has remained active in charity and other media work since a 2011 infidelity scandal led to her separation from husband Arnold Schwarzenegger.
She made an appearance on "Today" in March during its papal coverage.
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