Although many songs featured in Hanna-Barbera cartoons were specifically written for the shows and films, there were just as many that weren't. Examples are:
The Huckleberry Hound Show
- Huckleberry Hound often sings "Oh My Darling, Clementine" off-key, sometimes altering the lyrics.
- Huck sings "By the Light of the Silvery Moon" to serenade Desert Flower in the telefilm The Good, the Bad, and Huckleberry Hound.
The Flintstones
- In "The Flintstone Flyer", Fred Flintstone and Barney Rubble sing "Funiculi, Funicula" as they fly back from bowling.
- Fred sings "Lucia" from Lucia Di Lammermoor in "The Split Personality".
- Fred sings a rocking version of "When the Saints Come Marching In", in "Hot Lips Hannigan".
- Wilma sings "Won't You Come Home, Bill Bailey" when she unknowingly auditions for The Happy Housewife Show in "The Happy Household".
- Betty and Barney sing "When You're Smiling" in "The Rock Vegas Caper".
- Fred and Barney have the Boy Scouts sing "Old MacDonald Had a Farm" in "Cave Scout Jamboree".
- The Swedish musicians sing "Wilma" in "Swedish Visitors". It had been written by Owe Thörnqvist a couple of years earlier.
- Pebbles and Bamm-Bamm sing "Open Up Your Heart and Let the Sun Shine In" in "No Biz Like Show Biz". This song had been recorded years before by a Sunday school choir.
- The Beau Brummelstones sing "Laugh, Laugh" in "Shinrock à Go-Go". In real life, this song was a hit for the Beau Brummels the same year that this episode aired.
- In "The Story of Rocky's Raiders", Lt. Rocky Flintstone sings "Frère Jacques" while he, Reggie Vanderock, and Mata Harock are fleeing from Baron Von Rickenrock.
- In "The Surprise Party", and a few other episodes, characters sing "For He's a Jolly Good Fellow."
Butch Cassidy and the Sundance Kids
- In the episode "Double Trouble", several songs are mentioned, but not sung. They include "Yesterday" by The Beatles; "Woodstock", written by Joni Mitchell and recorded by Crosby, Stills, Nash and Young, and Matthews' Southern Comfort, as well as by Mitchell herself; and "Alice's Restaurant" by Arlo Guthrie.
The New Shmoo
- The show had a segment called "Sing Along With Shmoo", during which Shmoo acted as a bouncing ball, while Mickey, Nita, and Billy Joe sang "Down by the Station", "The Old Gray Mare", "John Jacob Jingleheimer Schmidt", and "The More We Sing/Get Together", all of which are well-known children's songs.
The Little Rascals
- In "Beauty Queen for a Day", Darla Hood sings "Indian Love Call" for the pageant.
- "Pete's Big Break" starts with Alfalfa's off-key rendition of "My Bonnie Lies over the Ocean".
Smurfs
- In the Season 9 episode "Hearts and Smurfs", Cupid's line, "Cupid, draw back your bow, and let your arrow go," is taken directly from "Cupid", which was a hit for Sam Cooke, Tony Orlando And Dawn, and for The Spinners.