Getting his licence at the age of 22, in the early 1980s, Leszek Czarnecki was one of the youngest diving instructors in Poland. In 1986, his passion for cave diving led him to set up his first commercial diving company —Przedsiębiorstwo Techniki Alpinistyczno-Nurkowej TAN S.A. In 1986–1990, he worked as a professional diver (with heavy diving equipment for underwater works). Diving is still his passion. He holds two – Polish and world – records. In September 2003, he beat the Polish record diving to 194 m in Boesmansgat cave in South Africa. The decompression lasted 4 hours and 48 minutes, at a water temperature of 16 °C. He was assisted by Nuno Gomes who holds two deep sea diving records – in the open sea he dived to 318.25 metres, and in caves – to 283 metres. In Mexico, Leszek Czarnecki beat the world record in the longest distance covered in the caverns – 17 km in the system of water-filled caves Dos Ojos on the Yucatán Peninsula in Mexico. In 2006, he took part in a North Pole expedition, and in a Bikini Atoll expedition to explore the wrecks. In 2007, he went on a trip across Siberian wilderness with diving in Lake Baikal, in 2008 – he went to Antarctica, and in 2010 – explored wrecks in the Truck Lagoon in Micronesia (where he dived several times), and in Galapagos.

In 1986, his passion for cave diving led him to set up a commercial diving company — Przedsiębiorstwo Hydrotechniki i Inżynierii TAN. He was the creator and main shareholder of Europejski Fundusz Leasingowy (European Leasing Fund) which he set up in 1991. This was the first and, eventually, the largest lease company in Poland. In 2001, he sold it to the French bank Credit Agricole for PLN 900 million, and became the CEO of Credit Agricole Poland. At that time, he was also managing other group’s companies, such as EFL, Lukas Bank, TU Europa, TU na Życie Europa, and Getin Service Provider S.A.

In 1993–1995, he was the deputy Chairman of the Supervisory Board, and later the CEO of Polbank S.A. (GMAC Bank). In 1996-1997, Leszek Czarnecki was the Chairman of the Supervisory Board of an insurance company based in Wrocław TU Europa na Życie S.A, and in 1997 he became the CEO of TU Europa S.A. and TU Europa na Życie S.A. for the next two years.

In 1998, Leszek Czarneci was granted the Wall Street Journal award for the Best CEO in Central Europe, as one of the 10 renowned businessmen in the region. In the same year, he also won the global finals of the Young Business Achiever, a contest that is held in Beijing.

In 2002-2003, he was the CEO and managing Director responsible for leasing and insurance at Credit Agricole Poland. Until the end of November 2004, he was the CEO of Getin Holding, and until May 2006 CEO of Getin Bank.

In October 2004, Leszek Czarnecki joined the honorary members of the Polish Association of Lease Companies, and in November he was included in the group of four individuals recognised as Entrepreneur of the Year from Eastern Europe by INSEAD, one of the best Business universities in Europe, and the French Minister of Finance. In September 2005, he received the prestigious Lesław Paga award honouring his achievements and personal contribution to the development of the financial services market in Poland.

Since June 2007, he has been the Chairman of Getin Holding’s Supervisory Board and a member of the Supervisory Boards of other companies belonging to the Getin Holding Group. Since the merger of Getin Bank with Noble Bank (January 2010), he has been the Chairman of the Supervisory Board of Getin Noble Bank. In 2006-2006, for €17.5 million, he purchased Poltegor Centre in 2005-2006, built in the mid-1970s in the city centre of Wrocław, and at that time the city’s tallest building. In place of the demolished building, Czarnecki, along with the investor LC Corp, built Sky Tower.

Two children from a previous marriage. Since 2008, married to Jolanta Pieńkowska. He holds a pilot’s licence.

In 2009, he instituted the first meeting of ‘Entrepreneurship – Initiative of Leszek Czarnecki’ – a series of debates held by leading schools of economics where Mr Czarnecki shared his knowledge and experience with students. In the same year, Leszek Czarnecki launched a contest named 'Studying, working, managing' aimed at supporting young entrepreneurs by financing laureates' Business ideas. The third edition finished in 2012. Leszek Czarnecki is proud to have established the charity foundation of Jolanta and Leszek Czarneccy, previously called LC Heart, which commenced its activities in Wrocław in 2007. So far, he has personally transferred PLN 55 million to the foundation. It is focused on levelling opportunities for children and youth.

In 2010, he won the Entrepreneur of the Year title in the opinion poll organised by the Polish Employers Organisation and Puls Biznesu. In 2011, he was recognised as the Business Leader of the Year by the Warsaw Business Journal.

The St. Antony's College Oxford Noble Foundation was established in October 2012 inaugurating the Contemporary Polish Studies Programme at Oxford University in the United Kingdom. The Programme is the first of its kind implemented abroad – an interdisciplinary study programme devoted to Poland and its post-1989 transformation. The programme operates within St. Antony’s College. The Oxford Programme’s founders and affiliates are Prof. Timothy Garton Ash and Prof. Norman Davies, as well as Prof. Margaret MacMillan, Warden of St. Antony’s College. On the Polish side the founder is Dr Leszek Czarnecki who with Getin Noble Bank donated PLN 6 million to the programme. Honorary Programme Patrons are the former Prime Minister of Poland Tadeusz Mazowiecki and Prof. Zbigniew Pełczyński.

In 2013, he was awarded the special award of the Warsaw Stock Exchange for his passionate and determined creation of new economic projects and visionary leadership in Business in the public market.

In 2014, Leszek Czarnecki was recognised by the editorial team of the WSE magazine GG Parkiet as the man of the capital market on the 25th anniversary of the democratic changes in Poland.