Paasonen is a Finnish surname. Notable people with the surname include:
Aladár Paasonen (1898–1974), Finnish military officer Sakari Paasonen (1935–2020), Finnish sport shooter Jani Paasonen (born 1975), Finnish rally driver Susanna Paasonen (born 1975), Finnish feminist scholar Heikki Paasonen (linguist) (1865–1919), Finnish linguist and ethnographer Heikki Paasonen (born 1983), Finnish television presenter