Katarzyna Niewiadoma (born 29 September 1994) is a Polish racing cyclist for Rabobank-Liv/giant, European under-23 road race champion.
Niewiadoma started racing bikes with local club WLKS Krakus BBC Czaja and soon emerged as one of the most promising women riders in Poland. In 2013 she won two national U-23 champion titles, finishing 4th in both the elite time-trial and elite road race. She also finished 5th in European Road Championships in the women’s U-23 road race.
Following these performances, she received an offer from professional team Rabobank-Liv/giant and became a stagiaire in August 2013. She participated in the Boels Ladies Tour, finishing 10th overall and winning the young rider classification. Niewiadoma was also selected for the UCI Road World Championships but she didn’t finish the elite women’s race.