Amell, the younger cousin of Arrow star Stephen Amell, announced the engagement via Instagram on Wednesday.
"She said yes!!!... I think. I can't really be sure," he captioned a photo of the two kissing, presumably post-engagement. "I'm going marry my best friend."
Ricci, 27, also shared the photo and confirmed the engagement via her Facebook page. "I did! I definitely, definitely said yes," she wrote. "I'm the happiest girl in the world."
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