Bob Newhart, the revered US comedian and star of two classic sitcoms known for his deadpan delivery, died on Thursday at the age of 94.

The Chicago native and titular star of game-changing sitcoms The Bob Newhart Show and Newhart in the 1970s and 80s, died at his home in Los Angeles after a period of short illnesses, his publicist Jerry Digney confirmed in a statement.

A former accountant who began moonlighting in comedy venues, Newhart first rose to fame in the 1960s for his observational humor and droll delivery. His breakthrough album, The Button-Down Mind of Bob Newhart, recorded over several days in Houston before Newhart had any stand-up experience, netted him Grammys for best new artist and album of the year in 1961.

“In 1959, I gave myself a year to make it in comedy; it was back to accounting if comedy didn’t work out,” he once said, according to Digney’s statement. Newhart was 30 years old and years into a career as a Chicago accountant when the album went No 1 on the sales charts, the first comedy album to do so.

The comic went on to dominate the sitcom landscape for nearly two decades with two beloved TV shows, first with The Bob Newhart Show, which aired on CBS from 1972 until 1978. The show, in which Newhart starred as a befuddled psychologist in Chicago, became one of the most popular sitcoms of all time.

The follow-up, Newhart, starred Newhart and Mary Frann as an author and his wife who open a rural inn in Vermont. It ran from 1982 until 1990 and featured one of the more admired finales in TV history, in which Newhart’s character wakes up next to his wife from the Bob Newhart Show, played by Suzanne Pleshette, suggesting the entire second series was a dream.

Newhart was nominated for several Emmys for his TV work, though he didn’t win one until 2013, for guest-starring as Arthur Jeffries on CBS’s The Big Bang Theory. He is also famous to younger audiences as Papa Elf, the adoptive father to Will Ferrell’s Buddy, in the 2003 holiday comedy Elf.

Mayim Bialik, who starred on The Big Bang Theory with Newhart said in a statement : “As a child, the Bob Newhart Show provided countless hours of enjoyment for me – it constituted some of my earliest training in the art of sitcom. When I got to work with alongside him on TBBT, it was absolutely a dream come true. He was effortlessly professional, poised, hilarious and incredibly approachable. Working with Bob was working in the presence of a true comedy legend.”

Born on 5 September 1929 in Oak Park, Illinois, George Robert Newhart ushered in a new style of comedy in the 1960s, breaking from the mold of vaudeville and Borscht Belt routines for bits based in observation and psychology. His performance style incorporated stammering, deadpan delivery and quietly subversive material that appealed widely; his debut was the first comedy album to top the Billboard charts, and his first two albums held the top two spots simultaneously, a feat not accomplished again until Guns N’ Roses in 1991.

In his later years, Newhart took on a number of feature film roles, including In & Out and Legally Blonde 2: Red, White & Blonde. He also continued performing standup into his 70s, giving about 30 shows a year as of 2006.

“Comedy has given me a wonderful life,” he said. “When I first started out in standup, I just remember the sound of laughter. It’s one of the great sounds of the world.”

The comedy great Carol Burnett posted on social media: “I had the great pleasure of working with Bob and being his friend. He was as kind and nice as he was funny. He will be missed.” The two worked together on The Carol Burnett Show.

Among others paying tribute to Newhart were Judd Apatow, Jamie Lee Curtis and Bill Prady. Apatow, who co-directed Bob and Don: A Love Story about the lifelong friendship of Newhart and Don Rickles, posted on social media: “I was so lucky to get to spend that time with my hero. His brilliant comedy and gentle spirit made everyone he encountered so happy.”

Prady reflected on his importance to comedy: “Hard to explain how important Bob Newhart was to every comedian and comedy writer who came after him.”

Curtis wrote in a tribute on her Instagram, “They will be laughing wherever people go when they leave us. God, he was funny! Bob Newhart. You will be missed!”

The comedian was inducted into the Academy of Television Arts & Sciences’ Hall of Fame in 1993, and won the second-ever Mark Twain prize for humor, presented by the Kennedy Center, in 2002. In 2007, The Button-Down Mind of Bob Newhart was chosen as one of 25 entries for the Library of Congress’s National Recording Registry.

Newhart’s wife, Ginnie, whom he married in 1963, died last year at the age of 82. He is survived by his four children, Robert, Timothy, Courtney and Jennifer, and 10 grandchildren.