Moore's "This Is Us" co-star Chris Sullivan confirmed her engagement to the musician, and revealed that he had already seen the ring, reported Entertainment Tonight.
"I was just in the studio with her her boyfriend, well now fiance, Taylor. He didn't say a word! He seemed a little effervescent, but he's always pretty effervescent... I know him very well," Sullivan said.
"He's quickly becoming one of my favourite people, and he and Mandy are an incredible couple."
Meanwhile, Moore's on-screen husband, Jon Huertas, who plays Miguel on the popular NBC drama, congratulated her and Goldsmith.