Kaley shared a black and white photo of Carol Ann on Facebook with a heartfelt caption that read, "Rest in peace hilarious, adorable, sweet Carol Ann Susi. You will forever be part of the Big Bang Theory family."
Kunal Nayyar, Mayim Bialik and Melissa Raunch each paid their respects on Twitter.
"Beloved Carol Ann Susi passed away, yes. The voice of Mrs Wolowitz. Oh Carol Ann," wrote Mayim, who stars on the hit US comedy as Amy.
Kunal – who plays Raj in the show - wrote, "My heart is broken. I will miss your smile. Your spirit is forever with us."
Beloved Carol Ann Susi passed away, yes. The voice of Mrs wolowitz. Oh Carol Ann. http://t.co/cx8h9pUQ7s— Mayim Bialik (@missmayim) November 12, 2014
Melissa, meanwhile, shared a portrait of the late actress, writing alongside, "So grateful to have known Carol Ann Susi who brought laughter & light with her always.
"She'll forever be in my heart," added the actress, who stars as Bernadette.
News of Carol Ann's death was confirmed in a joint statement released on Wednesday by CBS and producers Chuck Lorre, Steven Molaro and Bill Prady.
My heart is broken. I will miss your smile. Your spirit is forever with us. http://t.co/AOmLTEV0ZF— Kunal Nayyar (@kunalnayyar) November 12, 2014
"The Big Bang Theory has lost a beloved member today with the passing of Carol Ann Susi, who hilariously and memorably voiced the role of Mrs Wolowitz," it read.
"Unseen by viewers, the Mrs Wolowitz character became a bit of a mystery throughout the show's eight seasons. What was not a mystery, however, was Carol Ann's immense talent and comedic timing, which were on display during each unforgettable appearance.
So grateful to have known Carol Ann Susi who brought laughter & light with her always. She'll forever be in my heart. http://t.co/ecSsW7buPQ— Melissa Rauch (@MelissaRauch) November 12, 2014
"In addition to her talent, Carol Ann was a constant source of joy and kindness to all. Our thoughts and deepest condolences are with her family during this time, and we will miss her greatly."