Joscho Stephan was born on June 23, 1979, in Mönchengladbach, then in West Germany. His father, Günter Stephan, had played in a cover band and taught him guitar from the age of six; Stephan then took classical lessons until he was fourteen. In 1993 he won a first prize at the state round of the Jugend musiziert competition, and he took first prizes at the state round of Jugend jazzt in 1993 and 1995 while turning toward jazz and rock. Unlike many gypsy jazz guitarists he did not grow up in a Sinti or Roma musical family, although German Wikipedia notes that his grandfather was Romani. He came across the records of Django Reinhardt by chance as a teenager and taught himself the style as the basis of his solo playing.

In 1997 he appeared as a newcomer at the Django Reinhardt Memorial Festival in Augsburg, and two years later he released his debut, Swinging Strings (1999), on Acoustic Music Records, the label of the guitarist Peter Finger, who is credited as producer on his next several albums. Guitar Player named Swinging Strings its CD of the month in July 2000, and Acoustic Guitar Magazine wrote in May 2004 that Stephan represented the future of gypsy jazz guitar. Four more albums followed on Acoustic Music Records: Swing News (2001), Django Forever (2003), the live Acoustic Live (2006), and Django Nuevo (2009). Their credits show a steady band, with his father on rhythm guitar, bassist Max Schaaf, and violinist Sebastian Reimann on several of them.

From 2009 he worked with the klezmer clarinetist Helmut Eisel, which produced Gypsy Meets the Klezmer (2012) and Bei dir war es immer so schön (2016) under the billing Joscho Stephan & Helmut Eisel Quartett. In between came Gypsy Meets Jazz (2010) and Gypsy Meets Groove (2014) with the bassist Olivier Holland, the second of them a program of jazz and pop standards that includes "All Blues," "Yardbird Suite," and "La Vie en Rose." His official biography says that Gypsy Meets Groove and his next album were each nominated for a German Record Prize. That next album was Guitar Heroes (2015), on which he invited three guitarists he admired: the Australian Tommy Emmanuel, the Dutch gypsy swing guitarist Stochelo Rosenberg, and Biréli Lagrène. It mixes his own tunes, including "Blues for Tommy," "Song for Biréli," and "Blues for Stochelo," with Django Reinhardt pieces, Carlos Santana's "Samba Pa Ti," George Harrison's "Something," and George Benson's "Breezin'." A live follow-up with the same title came out in 2022.

Rhythm guitarist Sven Jungbeck began working with him in 2016, and by 2018 the Joscho Stephan Trio consisted of Stephan, Jungbeck, and bassist Volker Kamp. That lineup recorded Paris-Berlin (2018), a vinyl album of German songs from the 1930s and 1940s released by Berliner Meister Schallplatten, and Live in Concert Volume One (2023). In 2018 he recorded Classic Meets Gypsy with the Marcus Schinkel Trio, a set built on classical themes, followed by Salon 18 (2019) and Get Back to the Beatles (2020). In 2019 he formed the Transatlantic Guitar Trio with the guitarists Richard Smith and Rory Hoffman, recording the first album in Goodlettsville, Tennessee, and Mönchengladbach; it came out in 2020, with Swing Invention in 2023 and Across Strings & Borders in 2025 to follow. Since 2020 he has also played as a duo with the guitarist Peter Autschbach, who is his partner on Sundowner (2021).

His performing history reaches well beyond Germany. His official biography reports concerts in Nashville, Chicago, San Francisco, and Detroit, at Birdland, and at Lincoln Center in New York, and a tour of Australia with Martin Taylor and Tommy Emmanuel; it also lists shared stages with Paquito D'Rivera, James Carter, Charlie Mariano, and drummer Grady Tate. In January 2025 he was invited to the event Breezin' with the Stars in Phoenix, Arizona, started by George Benson, as both a guitarist and an instructor. His duo album Highwire with the pianist Cornelius Claudio Kreusch came out in 2025, as did the Joscho Stephan Trio's studio album Take-Off, whose guests are John Petrucci, Tommy Emmanuel, Matteo Mancuso, and Jerry Douglas; some of them recorded their parts from far away. He has run an online gypsy guitar academy since 2013, and his own website lists workshops through 2027, including Dresden in October 2026 and Tuscany in August 2027. His main concert instrument is a fully acoustic D-hole guitar built by Jürgen Volkert of Lauf an der Pegnitz.

Stephan is known for playing classical themes, jazz standards, and pop songs in the gypsy jazz idiom that Django Reinhardt developed in the 1930s, with the swung rhythm-guitar "pump" of the Hot Club format, usually carried by his father or Sven Jungbeck, and often a violin, as in the Stéphane Grappelli partnership. Because he learned the style from records rather than inside a Sinti family tradition, he has felt free to carry it elsewhere: German Wikipedia names blues, rock, country, and Latin jazz as further influences, and his albums bring in klezmer (with Helmut Eisel), the Beatles, Beethoven-based pieces (with Marcus Schinkel), Christmas songs, and a three-guitar program with Richard Smith and Rory Hoffman. Reviewers and magazines singled out his technique from the debut on, and the guitarists who joined him on Guitar Heroes and Take-Off span gypsy jazz, fingerstyle, rock, and Dobro playing. He writes much of his own material, such as "Créateur Immobilier" and "Papillon," and has composed tributes to fellow guitarists, among them "Song for Biréli" and "Blues for Stochelo."