Blair, 38, and Bleick, founder and creative director for EVER fashion line, met while collaborating for the brand and have been dating about a year, according to a friend.
"They are ecstatic," says the friend. "They couldn't be happier."
The actress was recently nominated for a Grammy for Best Spoken Word Album for Children for the audio book Anne Frank: The Diary Of A Young Girl: The Definitive Edition. She'll next be seen in the drama Dark Horse costarring Christopher Walken.