He graduated from the Faculty of Law and Administration of the Jagiellonian University in Krakow in 1989. After completion of judicial training, he passed judicial exam in September 1991, and in November 1993 qualified as legal advisor. After graduating from the studies Wiesław Oleś was i.a. a member of the Regional Accounting Chamber in Kraków, program consultant of the United States Agency for International Development (USAID) and cooperated with i.a. the Harvard Institute for International Development. He is the creator and co-founder of the Legal Office of Legal Advisors "Oleś & Rodzynkiewicz" Sp. k. currently "Oleś, Rysz, Sarkowicz" and the Chairman of the Supervisory Board of Towarzystwo Funduszy Inwestycyjnych Forum SA.  
Wiesław Oleś specializes in establishing and restructuring of investment structures and tax matters including cross-border transactions.
Wiesław Oleś is the author of publications in the field of commercial law: articles in "Rzeczpospolita", "Territorial Self-Government", "Community", book "Communal Companies". He is also co-author, with  dr Mateusz Rodzynkiewicz, of the following books: "Mergers of joint-stock companies - legal aspects" (1998) and "The transformation of a limited liability company into a joint stock company" (1999) and the commentary "Tax on civil law transactions" (2013) in cooperation with M. Gargul.