Jonáš Mareček (born 13 February 2001) is a Czech biathlete.

[2] He made his World Cup debut in January 2021 in the relay race in Oberhof.

[3] He participated in an individual World Cup race for the first time in March 2022 in Otepää, where he finished 48th in the sprint with one shooting miss.

[5] He was awarded 2nd place in the Vysočina Region Athlete of the Year poll in 2021 in the Junior Boys category.

[6] He was also recognized in the Vysočina Region Athlete of the Year poll in 2022 in the Junior Boys category.