Ravenscroft was born in Norfolk, Nebraska. He served as a navigator in the WWII Air Transport Command before settling in Hollywood.
An accomplished singer, he performed with The Sportsmen, The Mellomen, The Johnny Mann Singers, and many major stars, including Jim Nabors and Elvis Presley. He is best known, however, for his mellifluous voiceovers, particularly as the voice of Tony the Tiger in both English and Spanish commercials for Kellogg's Frosted Flakes cereal. In 1996, he and his wife June retired in Southern California, although he still did occasional work as "Tony" until his death.
His voice can be heard in several Disney theme park attractions, including The Haunted Mansion (as the lead singing bust), Walt Disney's Enchanted Tiki Room (as Fritz, Tangaroa and some of the Tiki Masks), Country Bear Jamboree (as Buff), Pirates of the Caribbean (as several singing pirates) and as a former narrator on the Disneyland Railroad.
He died in his home in Fullerton, California on May 22, 2005.
- Pinocchio (1940) - Monstro
- The Nifty Nineties (1941) - Singer
- Springtime for Pluto (1944) - The deep-voiced singing caterpillar before it transforms
- Make Mine Music (1946) - Singer
- Cinderella (1950) - Additional voices
- Alice in Wonderland (1951) - Card Painter
- Peter Pan (1953) - Chorus Singer
- Lady and the Tramp (1955) - Al the Alligator
- The Story of Anyburg, U.S.A. (1957) - Cyrus P. Sliderule
- Paul Bunyan (1958) - Paul Bunyan
- Sleeping Beauty (1959) - Singer (uncredited)
- One Hundred and One Dalmatians (1961) - Captain
- The Sword in the Stone (1963) - Sir Bart
- Dr.Syn: The Scarecrow of Romney Marsh (1963) - Singer (uncredited)
- Mary Poppins (1964) - Hog/Andrew's Whimper (uncredited)
- The Jungle Book (1967) - Shere Khan (singing voice), Colonel Hathi's crew (uncredited)
- The Aristocats (1970) - Billy Boss
- Bedknobs and Broomsticks (1971) - Singer
- The Many Adventures of Winnie the Pooh (1977) - Singer (uncredited)
- The Small One (1978) - The Potter
- The Brave Little Toaster (1987) - Kirby
- The Brave Little Toaster to the Rescue (1998) - Kirby
- The Brave Little Toaster Goes to Mars (1999) - Kirby