AceShowbiz - Bob Newhart has sadly left this world. The legendary comedian passed away at the age of 94 on Thursday morning, July 18 at his home in Los Angeles, and upon learning of the news, fellow celebrities were quick to pay tributes to him.

Confirming the comedy icon's death was his publicist, Jerry Digney. Jerry said in a statement that the funnyman died after a "series of short illnesses."

Judd Apatow, who directs popular comedy films like "The 40-Year-Old Virgin", took to Instagram to remember Bob. "Bob Newhart was as funny as they come. The best stand up, the best situation comedy star, the kindest soul," he penned.

"It was the thrill of a lifetime to spend some time with him when we made Bob and Don - A Love Story. I watched thousands of hours of his work growing up and he made my life much happier and did the same for the world," the filmmaker added. "Link to the doc is in my linktree."

Fellow comic Billy Crystal wrote on X, formerly Twitter, "@BobNewhart has passed away. A great comedian, a gentle wonderful man. In '60 he won 3 Grammy Awards! Best New Artist,ALBUM OF THE YEAR and Best Comedy performance. Only comedian to win BNA and Album of the year!" He continued gushing, "Amazingly he was an accountant until he was 30 yrs old. His sitcom was perfection. Loved by everyone who knew him. He was a great one."

Bob's "The Big Bang Theory" co-stars also remembered him, including Kaley Cuoco. "What a dream it was to witness the genius that was Bob Newhart. He was classy, kind, generous and absolutely hilarious," Kaley wrote on Instagram Story alongside a picture of the two in a scene together on the series. "Every take - every time. Icon forever."

Iain Armitage, who stars on the show's prequel spin-off, "Young Sheldon", penned on his own Instagram Story, "Thanks for being such an inspiring Professor Proton and such an incredible human being. Thinking of you and all who loved you today."

Bob, who was in the show business for over six decades, was most remembered for his roles in the CBS series "The Bob Newhart Show", which ran from 1972 to 1978, and "Newhart", which ran from 1982 to 1990. He was also known for his deadpan humor, standup comedy and roles in "Legally Blonde 2", "Elf", "ER" and the 2008 flick "The Librarian: The Curse of the Judas Chalice".

Bob is survived by his four children, sons Robert and Timothy, and daughters Jennifer and Courtney, as well as 10 grandchildren. His wife Ginnie, whom he married in 1963, died in April 2023.