Katarzyna Janina Łaniewska-Błaszczak (born 20 June 1933) is a Polish actress, opposition activist in the Polish People's Republic, and a political activist since 1989. She was born in Łódź, Poland. From 1970 to 1974, she starred in the comedy series Czterdziestolatek.
In the Polish parliamentary elections in 2011, Łaniewska was the nonpartisan candidate to the Senate on behalf of the Law and Justice party in Warsaw. She received nearly 100 thousand votes (nearly 31%).
She was the president of the Warsaw branch of the Association of Polish Artists from 1992 to 2006. She served on the Skolimowska Commission of the Main Board of the Polish Actors Association.
From 1954 to 1964, she was married to actor Ignacy Gogolewski.