Spelling later graduated from Southern Methodist University in 1949, where he was a Cheerleader.
Spelling made his first appearance as an actor in a film as Harry Williams in Vicki, directed by Harry Horner, in 1953. That same year, he appeared in the TV series I Led Three Lives and in two episodes of Dragnet. Spelling appeared in an episode of I Love Lucy in 1955 ("Tennessee Bound"), and continued to appear in films and TV (often uncredited) over 25 times by 1957, appearing briefly as an actor in 1963, 1995, and 1998 (all uncredited.)
Spelling sold his first script to Jane Wyman Presents in 1954. He guest starred that same year as a dogcatcher in the premiere episode of the CBS situation comedy, Willy, starring June Havoc as a young Lawyer in New Hampshire, who later relocates to New York City to represent a vaudeville troupe. Two years later, Spelling began to achieve considerable experience as a Producer and additional credits as a script Writer working on the Four Star television series Zane Grey Theater, which aired between 1956 and 1961. Of the 149 episodes in that series, he wrote no fewer than twenty of the teleplays and produced a significant number of others.
Beginning in 1965, Spelling began an award-winning legacy of producing successful television shows including The Mod Squad, The Rookies, Charlie's Angels, Fantasy Island, The Love Boat, Dynasty, Beverly Hills, 90210 (which starred his daughter Tori), 7th Heaven, Charmed, Jane's House and Sunset Beach. Spelling founded Spelling Entertainment in 1965, alongside partnerships with comedian/actor Danny Thomas (Thomas-Spelling Productions, 1966–1972), and television/film Producer Leonard Goldberg (Spelling-Goldberg Productions, 1972–1986) He produced the unsuccessful situation comedy The San Pedro Beach Bums in 1977.
Thomas-Spelling Productions was a television production company formed by Comedian Danny Thomas and Producer Aaron Spelling on April 15, 1966 as a partnership with 24 properties. Thomas continued his existing partnership, T&L Productions, with Sheldon Leonard. The company adapted its name by July 18, 1966 when it announced the financial involvement of ABC with its first show, Range (later Rango), a half-hour comedy western starring Tim Conway. and its rented space on Desilu Productions' Gower lot. ABC also pick up another show for a pilot, just in an outline treatment, in The Guns of Will Sonnett. Thomas-Spelling Productions' active operations ended with the last season of The Mod Squad in 1972. Spelling formed a new partnership with Leonard Goldberg, Spelling-Goldberg Productions.
On September 15, 1978, Spelling was honored with a star on the Hollywood Walk of Fame located at 6667 Hollywood Blvd. In 1996, he was inducted into the Television Hall of Fame.
In 1988, Spelling bought the 6-acre (2.4 ha) property of Bing Crosby's former Los Angeles house. He demolished the property and built a 123-room home on the lot in 1991. Known as "The Manor", it has 56,500 square feet (5,250 m) of floor space and is the largest single-family home in Los Angeles. Spelling's widow Candy listed the home for sale in 2008 for $150 million. Heiress Petra Ecclestone ultimately purchased the property for $85 million in 2011 through a brokered agreement that was developed by Brandon Davis, the brother of Jason Davis and grandson of wealthy industrialist, Marvin Davis.
In 2004, Spelling was portrayed in two television movies: Dan Castellaneta portrayed Spelling in Behind the Camera: The Unauthorized Story of Charlie's Angels, and Nicholas Hammond portrayed Spelling in television movie Dynasty: The Making of a Guilty Pleasure.
On August 27, 2006, Spelling was posthumously honored at the 58th Annual Primetime Emmy Awards by former employees Joan Collins, Stephen Collins, Heather Locklear, Farrah Fawcett, Kate Jackson and Jaclyn Smith.
On April 4, 2007, it was announced that 7th Heaven's May 13, 2007, episode, the last before the series finale, would be dedicated to Spelling. When 7th Heaven ended its run, it was touted by the network as being Spelling's longest-running series and the longest-running "family drama" in American television history.
As of 2009, Spelling, through his eponymous production company Spelling Television, holds the record as the most prolific television Writer and Producer in US television history, with 218 Producer and executive Producer credits. Forbes ranked him the 11th top-earning deceased Celebrity in 2009. Aaron's favorite actor was Norman Alden.