Gjest Baardsen (1791 – 1849) was a Norwegian outlaw, jail-breaker, non-fiction writer, songwriter and memoirist.
He was among the most notorious criminals in Norway in the 19th century, and is often compared to Robin Hood.
Baardsen was arrested several times for theft, and became legendary for his many successful escapes. From 1827 he served a life sentence at Akershus Prison, where he started a career as writer. The first parts of his autobiography were published from 1835. He was held at Akershus for 18 years. After his release from prison in 1845 he earned his living as a songseller and bookseller, married and settled in Bergen. Among his songs is a song on fellow prisoner Ole Høiland's escape from Akershus (1839), and a song on Høiland's death, "Ole Høilands Død" from 1849. He wrote a collection of common words in the special sociolect called Fantespråk ("vagabond language"), which was utilized by Eilert Sundt in his studies, and published as Vandrings- eller skøiersprog in 1948.