One-day races and Classics Jan Tratnik (born 23 February 1990 in Ljubljana) is a Slovenian cyclist, who currently rides for UCI WorldTeam Red Bull–Bora–Hansgrohe.

Tratnik started cycling at the age of 17 on the advice of Borut Božič who noticed him during a mountain bike competition organized by his school.

He also finished second overall in the Giro delle Regioni, an event on the UCI Under 23 Nations' Cup calendar, and competed at the under-23 world championships both years.

However, he was let go at the end of the season after a lack of results, largely due to an eating disorder causing him to lose an unhealthy amount of weight, forcing him to rejoin Radenska in 2012.

Tratnik's results for Amplatz–BMC caught the attention of Polish UCI Professional Continental team CCC–Sprandi–Polkowice, who signed him on a two-year contract starting in 2017.

[16] In his second season with the team, Tratnik maintined this form, winning the final stage of the Settimana Internazionale di Coppi e Bartali in Late, a time trial, followed by Volta Limburg Classic a week later.

[11] Tratnik started the 2024 season strong, taking his biggest one-day race victory yet: the Omloop Het Nieuwsblad in a two-man sprint against Nils Politt.