Pardo was hired for his first radio position at NBC affiliate WJAR in Providence in 1938.

Pardo married Catherine Lyons (d. 1995) in 1938. The couple had five children.

Pardo was born in Westfield, Massachusetts. His parents, Dominick Senior and Viola Pardo, were immigrants from Poland who owned a bakery. He spent his childhood in Norwich, Connecticut and Providence, Rhode Island. He graduated from Emerson College in 1942.

He joined NBC full-time as an in-house announcer in 1944, remaining on the network staff for 60 years. The radio programs on which he worked as an announcer include Barrie Craig, Confidential Investigator, the sci-fi shows X Minus One and Dimension X.

Pardo made his mark on game shows for NBC as the voice of the original The Price Is Right from 1956 until it moved to ABC in 1963. Pardo’s next show was Jeopardy!, which he announced from 1964 until the original version of the series ended in 1975. Pardo also announced New York–based NBC game shows such as Three on a Match, Winning Streak, and Jackpot!, all three of which were Bob Stewart productions.

Pardo was the on-duty live booth announcer for WNBC-TV in New York and the NBC network on November 22, 1963, and he was the first to announce to NBC viewers that President John F. Kennedy had been shot in Dallas, Texas.

His best known announcing work was for the television series Saturday Night Live. His was the fourth voice heard on the show’s premiere episode in 1975, after the first cold open sketch featuring Michael O’Donoghue, John Belushi and Chevy Chase. Pardo remained the program’s announcer except for one season (1981–1982), when it was announced by Mel Brandt or Bill Hanrahan. After “Live from New York, it’s Saturday Night!”, which is cried out at the end of the cold open, Pardo announces the show’s title, then names the cast members and musical guests in a voice-over during the opening montage. According to Pardo, his Saturday Night Live announcing booth during his tenure at Studio 8-H was almost exactly where Arturo Toscanini stood when conducting the NBC Symphony Orchestra in Rockefeller Center from 1937 to 1950.

In December 1976, Pardo participated in a musical performance by Frank Zappa, reciting a verse of the song “I’m the Slime”. Pardo subsequently reprised this role on the live-recorded version of the song for the Zappa in New York album (it was not featured on the first release in 1978, but it appears on the 1993 CD re-release). He also provided narration for the songs “The Illinois Enema Bandit” and “Punky’s Whips” (a business dispute between Zappa and his record company of the time led to “Punky’s Whips” being removed from the 1978 album, but the song was reinstated on the 1993 CD).

In 1989, he participated in the recording “I Beg Your Pardon” by Canadian synthpop band Kon Kan, which was an international hit single.

Pardo nominally retired from NBC in 2004. However, he continued to announce for Saturday Night Live at the behest of executive producer Lorne Michaels, initially under the assumption that a permanent replacement would be found quickly. In 2006, he began prerecording his announcements from a studio in his Arizona home. That arrangement lasted only a few episodes before producers insisted that they needed him in Studio 8H, and he resumed weekly flights to New York. On Saturday, February 23, 2008, Pardo appeared at the closing of Saturday Night Live to blow out the candles on his 90th birthday cake. During this period, Pardo missed approximately five episodes due to illness; cast member Darrell Hammond (who would be Pardo’s successor following his death) filled in for him but was uncredited.

Upon his induction into the Rhode Island Radio Hall of Fame on May 14, 2009, Pardo suggested that the May 16, 2009 episode of Saturday Night Live would be his last. However, he subsequently returned for the show’s 35th season. Starting with the 36th season, Pardo once again began pre-recording his parts from his home in Arizona instead of performing live in New York City.

In 2010, Pardo was inducted into the Television Hall of Fame.

Pardo died in his sleep on August 18, 2014 in Tucson, Arizona, at the age of 96.