Gold made her professional debut in 1973, while still in her last year of school, in the Christmas pantomime Dick Whittington and His Cat, as Fairy Bowbells, at the Malvern Festival Theatre. She played in the musical Hair on tour in Britain in 1974. In 1975–76, she played Rachel in Joseph and the Amazing Technicolor Dreamcoat at the York Theatre Royal and then on tour (as Rachel and Potiphar's Wife).
In 1977, Gold joined The Muppet Show, during the show's second season, where Jim Henson trained her as a puppeteer. She played several characters during her four seasons with the show, including Annie Sue Pig. She also sang on several of The Muppets' albums and was often paired vocally with Jerry Nelson. She was a puppeteer in the films The Great Muppet Caper (1981) and The Dark Crystal (1982), and she appeared in various other Muppet series and specials. Muppet chronicler Christopher Finch wrote that Gold was "the most versatile female puppeteer to work on The Muppet Show [and] the only British member of the cast." During these years, she continued to appear in musicals and plays in between her commitments to The Muppets. Among her non-puppeteering television appearances, Gold was featured as Mrs Tyler, a Goodwife, in the first series episode "Witchsmeller Pursuivant" of Blackadder (1983). The same year, she appeared as Maureen Bedford in episode two of For 4 Tonight, a talk-show spoof. In 1991, she played the domineering Private Elsa Bigstern in two episodes of 'Allo! 'Allo!.
From 1984 to 1986, and occasionally thereafter, Gold was a lead puppeteer and voice on the satirical television show Spitting Image and was the lead singer (as Nancy Reagan) on their first single, "Da Do Run Ron", a pastiche of The Crystals' "Da Doo Ron Ron", released in 1984. Gold was the first puppeteer hired for the show and "helped out with the Spitting Image pre-pilot, so she naturally became the 'consultant' for the hiring [and training] of the rest" of the puppeteers. Peter Fluck, a creator of the show, commented, "Louise Gold always did the Queen and the mannerisms and facial expressions she put into it were wonderful. It was very exciting because this lump of clay we modelled with a fairly neutral expression came to life."
Gold's later puppeteering work includes the title character, Fughetta Faffner, in The Ghost of Faffner Hall (1989), a Muppet music education TV Series. She played several of the characters on Roland Rat The Series broadcasts in 1986 and 1988, Sesame Street in the early 1990s, on Mopatop's Shop in the early 2000s, and in The Muppet Christmas Carol (1992) and Muppet Treasure Island (1996). In 1992, Gold played Sally Spook in The Spooks of Bottle Bay. In 1995 and 1997, she played characters on series 2 and series 3 of with Stinky and Jake, including Tizzy Bee, an early example of a computer generated image puppet.