Originally, the only cast member who was supposed to sing was Shirley Jones. However, after the producers heard David Cassidy's demos of the songs, they decided to let him sing as well.
Danny Bonaduce revealed years later that during the run of the series, many people actually thought the kids played their own instruments and thought that they should perform live. However, the only member of the cast to actually tour and perform was David Cassidy who at the time had a successful singing career in the USA and UK.
David Cassidy is actually playing guitar in the first episode as the kids go through their sound check.
Originally, the show was to star the real life musical family The Cowsills. However, they backed out when the producers decided to have Shirley Jones take over the role of the mother from the group's actual matriarch, Barbara Cowsill.
Several songs credited to the Partridge Family actually charted. In fact the very first single, "I Think I Love You" went to number-one and sold over 4 million copies. Other hits included "I'll Meet You Halfway", "Doesn't Someone Want to Be Wanted" and "I Woke Up in Love This Morning".
The Partridges had a dog named Simone in the first season. However, it was gone after the first few appearances of the second season.
During the first season, the theme song had a different arrangement, different lyrics and even a different title, "When We're Singing". However, during the second season the more familiar arrangement of the theme song with the more familiar title "Come On Get Happy" was used and remained the theme song throughout the run of the show.
The name of the Partridge's home town was San Pueblo, California.
Reuben had a nephew named Alan who was seen in one episode. He was going to be the Partridges' assistant manager; however, he wound up being a stand up comedian.
Reuben had an airline stewardess girlfriend named Bonnie Kleinschmidt (played by Elaine Giftos) who was often mentioned and appeared on a couple of occasions.
The occasional roles of Shirley's parent's Fred and Amanda Renfrew were played by Ray Bolger and Rosemary DeCamp. However, during the final season, the role of Grandpa Renfrew was taken over by Jackie Coogan and his name, with no explanation, was changed to Walter.
The name of Shirley's late husband was never mentioned throughout the run of the series.
The character Danny Partridge was ranked #6 in TV Guide's list of "TV's 10 Biggest Brats" (27 March 2005 issue).
During the filming of the pilot and a few early episodes, Susan Dey had to live with a guardian until she turned 18 in December, 1970.
In many of the early episodes, Shirley Jones would provide narration. However, after a couple of episodes the narration was dropped.
"I Think I Love You" was recorded on 11 May 1970 at Western Recorders in Hollywood. Produced by Wes Farrell, and arranged by Billy Strange, the vocals were performed by David Cassidy, Shirley Jones, Ron Hicklin, Stan Farber, Jackie Ward, Tom Bähler, and John Bahler. The harpsichord solo was played by Larry Knechtel.
The house in which the Partridges reside was a combination of a studio set for the interiors and an exterior facade on the back lot at Warner Brothers "Ranch" complex in Burbank. The exterior house was also used as Mrs Kravitz house in the TV series "Bewitched" (1964),. During the first season of the "Partridge Family" and the last season of "Bewitched", both shows used the same exterior of the house as the residence for their respective characters. The house was also seen in the movie "Pleasantville" (1998) as Margaret's house and the TV series "Life Goes On" (1989) as the residence of the Thacher family. Over the years it has been remodeled and painted different colors but is still recognizable - the front step and the shape of the roof are giveaways.
The exterior of the Partridge house is the same exterior used in "Bewitched", "The Donna Reed Show", and "Til Death".
The series was based on the real-life family group, The Cowsills. The children were interviewed by the producers, but it was decided that they were too old to play the parts as written for the TV series.
According to the 1970 TV Guide Fall Preview issue, the name of Shirley Jones' character was supposed to be Connie Partridge.
Jeremy Gelbwaks was forced to leave after the first season when his father's job took the family out of California; he was replaced by Brian Forster. According to Bernard Slade, ABC did not receive a single letter of complaint about the change.
The actual singers for the Partridge Family are: Shirley Jones, David Cassidy, John Bahler, Tom Bähler, Jackie Ward, and Ron Hicklin.
The Partridge Bus was painted in a style inspired by the geometric paintings of Piet Mondrian.
The Patti Partridge doll was first introduced on "Dora, Dora, Dora". Tracy, was shielding the doll's ears with her fingers to block out Dora's off-key warbling. The doll, although seen occasionally on several episodes before, was never seen again. According to star Suzanne Crough, she keeps the doll in her own personal collection.
The character Ricky was added during the final season as it was felt a new younger child among the cast would add a boost to the ratings. Due to the popularity of the Jackson Five, Michael in particular, producers considered casting an African American Child for the part of Ricky.
Ruben's middle name, is Clarence.
The title refer to the musical "The Sound of Music" which opened on Broadway (New York City) at the Lunt-Fontanne Theatre on November 16, 1959, ran for 1443 performances and won (in a tie) the 1960 Tony Award for the Best Musical.