According to her Facebook profile, Witkowska arrived on top of the legendary mountain at 5:59 a.m. on Friday Polish time.
With her feat, Witkowska became the second Polish woman in history to climb the K2, after Wanda Rutkiewicz, who achieved it in 1986.
Witkowska, 56, has numerous mountaineering successes to her name, including Mount Everest (8,848 metres) in 2013, Manaslu (8,156 metres) in 2018, and Lhotse (8,516 metres) in 2019.
In 2016, with the ascent of Mt. Vinson in Antarctica, she completed the Seven Summits challenge of scaling the highest mountain on each continent.
Witkowska has also been successful in sailing.
An author of over a dozen travel books and a regular contributor to various publications, she has visited 180 countries.
(mk/gs)