The Carrie Diaries star, 23, announced his tragic news of his mom's death to fans via Twitter on Thursday afternoon. A source tells Us Weekly his mom had been battling cancer.
"Lori Butler, my mom, my hero, & my best friend passed away this morning," the heartbroken actor wrote. "Lets all celebrate her. I love you and will miss you every day Mom."
Hudgens, 25, who has been dating Butler since 2011, was evidently devastated by the news, too. Sending a public message of support to her boyfriend, The Frozen Ground actress retweeted his words with the addition "I miss you already mama."
"#ripLoriButler #celebrateLori," the actress added. "Spread the love for Lori."
Hudgen's own mom, Gina Hudgens, also expressed her sympathies and sadness, with a heartfelt message.
"Lori, RIP. You'll be forever alive in our hearts & mind," she tweeted. "You'll always be our angel in heaven watching over us. U will be missed!"