"I now pronounce us Mr. and Mrs. Beech! Ahhh," the actress, 23, tweeted on Friday. She also posted a picture from their nuptials, for which Grimes wore a black wedding dress by Vera Wang.
The couple announced their engagement in December after meeting on the set of Grimes' CW series last spring.
The 90210 series finale airs Monday at 8/7c on The CW. What do you think of Grimes' dress?