Caesar was the youngest of three sons born to Jewish immigrants living in Yonkers, New York. His father was Max Ziser and his mother was Ida (née Raphael). They likely were from Dambrowa Tarnowska, Poland. Reports state that the surname “Caesar” was given to Max, as a child, by an immigration official at Ellis Island. This is an urban myth. According to Marian L. Smith, senior historian of the U.S. Citizenship and Immigration Service, there is no known case of a name changed at Ellis Island. Max and Ida Caesar ran a restaurant, a 24-hour luncheonette. By waiting on tables, their son learned to mimic the patois, rhythm and accents of the diverse clientele, a technique he termed double-talk, which he used throughout his career. He first tried double-talk with a group of Italians, his head barely reaching above the table. They enjoyed it so much that they sent him over to a group of Poles to repeat his native-sounding patter in Polish, and so on with Russians, Hungarians, Frenchmen, Spaniards, Lithuanians, and Bulgarians. Sid Caesar’s older brother, David, was his comic mentor and “one-man cheering section.” They created their earliest family sketches from movies of the day like Test Pilot and the 1927 silent film Wings.  At 14, Caesar went to the Catskill Mountains as a saxophonist in the Swingtime Six band with Mike Cifficello and Andrew Galos and occasionally performed in sketches in the Borscht Belt.

After graduating from Yonkers High School in 1939, Caesar left home, intent on a musical career. He arrived in Manhattan and worked as an usher and then a doorman at the Capitol Theater there. He was ineligible to join the musicians’ union in New York City until he established residency, but he found work as a saxophonist at the Vacationland Hotel, a resort located in the Catskill Mountains of Sullivan County, New York. Mentored by Don Appel, the resort’s social director, Caesar played in the dance band and learned to perform comedy, doing three shows a week. He audited classes in clarinet and saxophone at the Juilliard School of Music. In 1939, he enlisted in the United States Coast Guard, and was stationed in Brooklyn, New York, where he played in military revues and shows. Vernon Duke, the composer of Autumn in New York, April in Paris, and Taking a Chance on Love, was at the same base and collaborated with Caesar on musical revues.

During the summer of 1942, Caesar met his future wife, Florence Levy, at the Avon Lodge in the Catskills village of Woodridge, New York. They were married on July 17, 1943, and had three children: Michele, Rick and Karen. After joining the musicians’ union, he briefly played with Shep Fields, Claude Thornhill, Charlie Spivak, Art Mooney and Benny Goodman. Later in his career, he performed “Sing, Sing, Sing” with Goodman for a TV performance.  Still in the service, Caesar was ordered to Palm Beach, Florida, where Vernon Duke and Howard Dietz were putting together a service revue called Tars and Spars. There he met the civilian director of the show, Max Liebman. When Caesar’s comedy got bigger applause than the musical numbers, Liebman asked him to do stand-up bits between the songs. Tars and Spars toured nationally, and became Caesar’s first major gig as a comedian. Liebman later produced Caesar’s first television series.

After the war, the Caesars moved to Hollywood. In 1946, Columbia Pictures produced a film version of Tars and Spars in which Caesar reprised his role. The next year, he acted in The Guilt of Janet Ames. He turned down the lead of The Jolson Story as he did not want to be known as an impersonator, and turned down several other offers to play sidekick roles. He soon returned to New York, where he became the opening act for Joe E. Lewis at the Copacabana nightclub. He reunited with Liebman, who guided his stage material and presentation. That job led to a contract with the William Morris Agency and a nationwide tour. Caesar also performed in a Broadway revue, Make Mine Manhattan, which featured The Five Dollar Date—one of his first original pieces, in which he sang, acted, double-talked, pantomimed, and wrote the music. He won a 1948 Donaldson Award for his contributions to the musical.

Caesar’s television career began with an appearance on Milton Berle’s Texaco Star Theater in the fall of 1948. In early 1949, Caesar and Liebman met with Pat Weaver, vice president of television at NBC, which led to Caesar’s first series, Admiral Broadway Revue with Imogene Coca. The Friday show was simultaneously broadcast on NBC and the DuMont network, and was an immediate success. However, its sponsor, Admiral, an appliance company, could not keep up with the demand for its new television sets, so the show was cancelled after 26 weeks—ironically, on account of its runaway success.

On February 25, 1950, Caesar appeared in the first episode of Your Show of Shows, initially the second half of the two-hour umbrella show, Saturday Night Review; at the end of the 1950–51 season, Your Show of Shows became its own, 90-minute program. Burgess Meredith hosted the first two shows, and the premiere featured musical guests Gertrude Lawrence, Lily Pons and Robert Merrill. The show was a mix of sketch comedy, movie and television satires, Caesar’s monologues, musical guests, and large production numbers. Guests included: Jackie Cooper, Robert Preston, Rex Harrison, Eddie Albert, Michael Redgrave, Basil Rathbone, Charlton Heston, Geraldine Page, Douglas Fairbanks Jr., Pearl Bailey, Fred Allen, Benny Goodman, Lena Horne and many other stars of the time. It was also responsible for bringing together the comedy team of Caesar, Coca, Carl Reiner, and Howard Morris. Many writers also got their break creating the show’s sketches, including Lucille Kallen, Mel Brooks, Neil Simon, Michael Stewart, Mel Tolkin and Sheldon Keller. Sid Caesar won his first Emmy in 1952. In 1951 and 1952, he was voted the United States’ Best Comedian in Motion Picture Daily’s TV poll. The show ended after almost 160 episodes on June 5, 1954.

A few months later, Caesar returned with Caesar’s Hour, a one-hour sketch/variety show with Morris, Reiner, Bea Arthur and other members of his former crew. Nanette Fabray replaced Coca, who had left to star in her own short-lived series. Ultimate creative and technical control was now in Caesar’s hands. The show moved to the larger Century Theater and the weekly budget doubled to $125,000. The premiere on September 27, 1954, featured Gina Lollobrigida. Everything was performed live, including the commercials.  Caesar’s Hour was followed by ABC’s short-lived Sid Caesar Invites You from January 26 to May 25, 1958. It briefly reunited Caesar, Coca, and Reiner, with Simon and Brooks among the writers.

In 1963, Caesar appeared on television, on stage, and in the movies. Several As Caesar Sees It specials evolved into the 1963–64 Sid Caesar Show (which alternated with Edie Adams in Here’s Edie). He starred with Virginia Martin in the Broadway musical Little Me, with book by Simon, choreography by Bob Fosse, and music by Cy Coleman. Playing eight parts with 32 costume changes, he was nominated in 1963 for a Tony Award for Best Leading Actor in a Musical. On film, Caesar and Adams played a husband and wife drawn into a mad race to find buried loot in the 1963 screwball comedy It’s a Mad, Mad, Mad, Mad World.

Nachman concludes that “the Caesar shows were the crème de la crème of fifties television,” as they were “studded with satire, and their sketches sharper, edgier, more sophisticated than the other variety shows.” Likewise, historian Susan Murray notes that Caesar was “…best known as one of the most intelligent and provocative innovators of television comedy.”  According to actress Nanette Fabray, who acted alongside Caesar, “He was the first original TV comedy creation.” His early shows were the “…gold standard for TV sketch comedy.” In 1951, Newsweek noted that according to “the opinion of lots of smart people, Caesar is the best that TV has to offer,” while Zolotow, in his 1953 profile for The Saturday Evening Post, wrote that “in temperament, physique, and technique of operation, Caesar represents a new species of comedian.”

However, his positive impact on television became a negative one for Broadway. Caesar fans preferred to stay home on Saturday nights to watch his show instead of seeing live plays. “The Caesar show became such a Saturday-night must-see habit—the Saturday Night Live of its day,” states Nachman, that “…Broadway producers begged NBC to switch the show to midweek.” Comedy star Carol Burnett, who later had her own hit TV show, remembers winning tickets to see My Fair Lady on Broadway: “I gave the tickets to my roommate because I said, Fair Lady’s gonna be running for a hundred years, but Sid Caesar is live and I’ll never see that again.”

After nearly 10 years as a prime-time star of television comedy with Your Show of Shows followed by Caesar’s Hour, his stardom ended rapidly and he nearly disappeared from the spotlight. Nachman describes this period:  Caesar slid into a personal and career abyss … [he] had no interest in movies … He would live and die by the tube. His career was short-circuited by alcohol and pills … The pressures of sudden stardom, of headlining and co-producing a weekly hit show, crushed him.

Caesar himself felt, “It had all come too fast, was too easy, and he didn’t deserve the acclaim.” Writer Mel Brooks, who also became his close friend, said, “I know of no other comedian, including Chaplin, who could have done nearly ten years of live television. Nobody’s talent was ever more used up than Sid’s. He was one of the greatest artists ever born. But over a period of years, television ground him into sausages.”

In 1977, after blacking out during a stage performance of Neil Simon’s The Last of the Red Hot Lovers, Caesar gave up alcohol “cold turkey”. In his 1982 autobiography, Where Have I Been?, and his second book, Caesar’s Hours, he chronicled his struggle to overcome his alcoholism and addiction to sleeping pills.

Throughout the 1970s and 1980s, Caesar continued to make occasional television and night club appearances and starred in several movies including Silent Movie and History of the World, Part I (both reuniting him with Mel Brooks), Airport 1975, and as Coach Calhoun in Grease and its sequel Grease 2 in 1982. In 1971, he starred opposite Carol Channing and a young Tommy Lee Jones in the Broadway show Four on a Garden.

In 1973, Caesar reunited with Imogene Coca for the stage play, The Prisoner of Second Avenue, written in 1971 by Neil Simon. Their play opened in Chicago in August 1973. That same year, Caesar and Max Liebman mined their own personal kinescopes from Your Show of Shows (NBC had “lost” the studio copies) and they produced a feature film Ten From Your Show of Shows, a compilation of some of their best sketches. In 1974, Caesar said, “I’d like to be back every week” on TV and appeared in the NBC skit-based comedy television pilot called Hamburgers.

In 1983, Caesar hosted an episode of Saturday Night Live, where he received a standing ovation at the start of the show and was awarded a plaque at the conclusion of the show declaring him an honorary cast member. He released an exercise video, Sid Caesar’s Shape Up!, in 1985. In 1987–89, Caesar appeared as Frosch the Jailer in Die Fledermaus at the Metropolitan Opera in New York. Caesar remained active by appearing in movies, television and award shows, including the movie The Great Mom Swap.  In 1996, the Writers Guild of America, West reunited Caesar with nine of his writers from Your Show of Shows and Caesar’s Hour for a two-hour panel discussion featuring head writer Mel Tolkin, Caesar, Carl Reiner, Aaron Ruben, Larry Gelbart, Mel Brooks, Neil Simon, Danny Simon, Sheldon Keller, and Gary Belkin. The event was taped, broadcast on PBS in the United States and the BBC in the UK, and later released as a DVD titled Caesar’s Writers.

In 1997, he made a guest appearance in Vegas Vacation and, the following year, in The Wonderful Ice Cream Suit in 1998 based on a Ray Bradbury novel. Also that year, Caesar joined fellow television icons Bob Hope and Milton Berle at the 50th anniversary of the Primetime Emmy Awards. Billy Crystal also paid tribute to Caesar that night when he won an Emmy for hosting that year’s Oscar telecast, recalling seeing Caesar doing a parody of Yul Brynner in The King & I on Your Show of Shows. Caesar performed his double-talk in a “foreign dub” skit on the November 21, 2001 episode of Whose Line Is It Anyway?

On September 7, 2001, Caesar, Carl Reiner and Nanette Fabray appeared on CNN’s live interview program Larry King Live along with actor, comedian and improvisationist Drew Carey.  In 2003, he joined Edie Adams and Marvin Kaplan at a 40th anniversary celebration for It’s a Mad, Mad, Mad, Mad World. In 2004, Caesar’s second autobiography, Caesar’s Hours, was published, and in 2006, Billy Crystal presented Caesar with the TV Land Awards’ Pioneer Award. In what TV Land called “…a hilarious, heartfelt, multilingual, uncut acceptance speech,” Caesar performed his double-talk for over five minutes.

In a November 2009 article in the Toluca Lake, California, Tolucan Times, columnist Greg Crosby described a visit with Caesar and his wife Florence at their home. Of the couple’s meeting, Florence said, “Well, I thought he was nice for the summer … I thought he would be just a nice boyfriend for the summer. He was cute-looking and tall, over six feet…. I was in my last year at Hunter College; we were still dating when Sid went into the service, the Coast Guard. Luckily he was stationed in New York so we were able to continue seeing each other, even though my parents weren’t too happy about it. They never thought he would amount to anything, that he’d never have a real career or make any money. But we were married one year after we met, in July of 1943.” She also pointed out, “You know, he’s not funny all the time. He can be very serious.” At the time of the interview, the couple had been married for 66 years.  Florence Caesar died on March 3, 2010, aged 88.

Caesar died on February 12, 2014, at his home in Beverly Hills, California, at the age of 91, after a short illness.  On Caesar’s death, Carl Reiner said, “He was the ultimate, he was the very best sketch artist and comedian that ever existed.” Mel Brooks commented, “Sid Caesar was a giant, maybe the best comedian who ever practiced the trade. And I was privileged to be one of his writers and one of his friends.” Jon Stewart and The Daily Show paid tribute to Caesar at the show’s close on February 12, 2014. Vanity Fair republished a brief tribute written by Billy Crystal in August 2005, in which he said of Caesar and his contemporaries:

I get nervous when I am with these giants. I always feel like I want to say, Thank you. I am blessed to have grown up in their time of perfection, to have witnessed the utter force of Sid. Live, uncut, daring but not risqué. Never stooping beneath themselves, Sid and this team of icons put forth a raucous, hilarious, and truthful brand of comedy that, 50 years later, is still funny and inspiring, and makes me think … What kind of comedy would I be doing if I hadn’t seen Sid Caesar? Would I be a comedian at all?  His interment was at Mount Sinai Memorial Park Cemetery.