MacDonald became a stand up comedian, performing in comedy clubs across Canada. MacDonald eventually moved to Los Angeles, California, and became a writer for the popular Roseanne television series. MacDonald is known for his biting sarcasm and distinct muttering and slurring delivery during his stand up shows. He is the brother of Canadian journalist Neil MacDonald.

Information about Norm's past is difficult to ascertain, since he is notorious for fabricating information about himself.

Norm's father was a math teacher. Norm has claimed that he was a student in his father's class, and that he had to call him "Mr. MacDonald" while in class. The preceding is true - His father (Percy) was his home room teacher for 2 years (Grade 6 & Grade 7) at Alexander Wolff School in the early 70's and his mother (Fern) was also a teacher in the same school on CFB Valcartier outside Quebec City. After completing Grade 7 at AWS he continued his education at Quebec High School in Quebec City.

There are a number of conflicting stories about Norm's educational background.

Norm dropped out of high school at the age of 15.
Norm attended Algonquin College in Ottawa, Ontario, majoring in broadcasting, but dropped out to pursue a career in show business.

MacDonald joined the cast of NBC's popular Saturday Night Live (SNL) program in 1993, where he occasionally did impressions of Larry King, Burt Reynolds, David Letterman, Charles Kuralt, Bob Dole and others.

However, his most notable position on SNL was his three-year stint as anchor of Weekend Update. Chevy Chase, the first anchor of WU, has noted that MacDonald is the only anchor since Chevy's tenure to have "done it right." His deadpan style was suited to the segment, although he did rely heavily on running gags, stereotypes, and general outrageousness, including his repeated references to the Germans and their love of Baywatch star David Hasselhoff, regular jokes about prison rape as well as the poor job status of 'crack whores' and some audacious comedic attacks on public figures such as O.J. Simpson and Michael Jackson. Throughout the infamous Simpson trial, MacDonald constantly pilloried the former football star and repeatedly suggested that Simpson was guilty of the brutal slaying of his wife Nicole. In the broadcast following Simpson's not guilty verdict, MacDonald opened Weekend Update saying: "Well, it's official: Murder is legal in the state of California."

In another particularly notorious item circa 1995, MacDonald attacked Michael Jackson after his divorce from Lisa-Marie Presley. He announced that the two had divorced citing irreconcilable differences: "She's more of a stay-at-home type, and he's more of a homosexual pedophile."

He followed this up a few episodes later with during a report about the singer's recent collapse and hospitalization. Referring to a report of how Jackson had decorated his hospital room with giant photographs of Shirley Temple, Norm stated that viewers should not get the wrong idea: "we'd like to remind you that Michael Jackson is in fact a homosexual pedophile." The outrageous joke elicited audible gasps of disbelief from some audience members.

On the February 24, 1996 show, MacDonald commented on the sentencing of John Lotter, who was convicted of brutally slaying transgender male Brandon Teena: "In Nebraska, a man was sentenced for killing a female crossdresser [sic] who had accused him of rape and two of her friends. Excuse me if this sounds harsh, but in my mind, they all deserved to die." [1]

Another uncomfortable moment occurred during the April 12, 1997 show (host Rob Lowe, musical guest Spice Girls), where, during a "Weekend Update" story about Tabitha Soren, he accidentally coughed in the middle of a sentence and, live on the air, muttered, "What the fuck was that?" The audience applauded and MacDonald laughed the error away (saying at one point "My farewell performance" and, in closing, "Maybe I'll see you next week"). NBC received a mere 3 complaints about the gaffe and MacDonald was not punished. In fact, he stumbled on a story the following week and, catching himself, said, very tongue-in-cheek, "Oh, drat!"

A particularly infamous joke never made it to air. Norm showed the famous photo of naked Vietnamese children running from a South Vietnamese napalm attack, and said, "In other news, Woody Allen is dating again!" Norm described the audience as projecting a "pure, crazy hate" directed at him.

MacDonald's time with SNL ended controversially at the end of 1997 when he was sacked from the "Weekend Update" segment upon the insistence of NBC West Coast Executive Don Ohlmeyer, who pressured the producers to remove him, stating that MacDonald was "not funny". Although it was an opinion shared by some, much of the SNL live audience still greeted him with heavy applause. Although it is only speculation, some believe that Don Ohlmeyer's friendship with O.J. Simpson — a celebrity whom Norm often antagonized on the show — may have fueled Ohlmeyer's decision. To this day, Ohlmeyer denies that, arguing that other NBC late-night comedians (e.g. Jay Leno, Conan O'Brien, and other SNL players) also constantly lampooned O.J. with little to no sanction, and that his decision was based solely on audience reaction through tapes he had personally reviewed. Despite the incident, MacDonald left the show the following year under decent terms with Ohlmeyer, who originally pushed for producer Lorne Michaels to give MacDonald a shot at the Weekend Update desk in 1994. His last appearance on the program as a cast member was on February 28, 1998, portraying a host of fictitious TV show entitled "Who's More Grizzled?," asking questions to mountain men characters played by that episode's host Garth Brooks and special guest Robert Duvall. In the sketch, Brooks' character remarked to MacDonald's character at one point, "I don't much care for you," to which MacDonald replied "Not a lot of people do."

After MacDonald left the show, his successor Colin Quinn gave a short monologue before his first starring role in a Weekend Update segment implying that Norm had shown him "the ropes" to being a Weekend Update anchor. Quinn asked the audience if they had ever gone to their favorite bar looking for their favorite bartender and found out the bartender had been replaced (by a less qualified man named "Steve"). After a brief pause, Quinn looked flatly at the audience and proclaimed, "Well I'm Steve," cementing the fact that everyone, including those behind the scenes, would indeed miss MacDonald's controversial anchorship. Only a few minutes after Quinn's "I'm Steve" remark, SNL castmember Will Ferrell appeared with Quinn as Chicago Cubs announcer Harry Caray. In a memorable performance, Ferrell continuously referred to Quinn as "Norm."