Agron, 30, and Marshall, 27, reportedly got engaged during the holiday season last year. Though neither confirmed the engagement, the actress seemed to have hinted at the special news in a New Year's tweet.
"Hope everyone had a gorgeous holiday season," she wrote on Jan. 4. "Happy 2016! Couldn't be more excited over here…"
While Agron has since stayed quiet on her nuptials, she did get into the wedding spirit in February, donning a wedding dress and veil for her role in Novitiate.
"Meanwhile, today on set. #NOVITIATE," she captioned an Instagram shot of her bridal look.