Peter "Pirre" Wallenberg Sr. (29 May 1926 – 19 January 2015) was a Swedish business leader who was chairman of Investor AB for ten years.

He served as chairman of Investor AB for ten years,[8] during which time he internationalised the firm and set in motion international mergers that created companies such as ABB, AstraZeneca and Stora Enso.

[10] Wallenberg was also a board member of the Federation of Swedish Industries (Sveriges Industriförbund), the Swedish National Committee of the International Chamber of Commerce, the Stockholm School of Economics Association (from 1988 to 2001[11]), Dillon, Read & Co. in the United States, Per Jacobsson Foundation in the United States and the Swiss Bank Corporation Advisory Board in Switzerland.

[12] He was also board member of the Stockholm School of Economics Association, Dillon, Read & Co. in the United States, Per Jacobsson Foundation in the United States, Lauder Institute and the Swiss Bank Corporation Advisory Board in Switzerland.

It was attended by the king Carl XVI Gustaf, Queen Silvia, Crown Princess Victoria, Prince Daniel, Prince Carl Philip, Stefan Löfven, Leif Johansson, Cristina Stenbeck, Pehr G. Gyllenhammar, Maud Olofsson, Karl-Petter Thorwaldsson, Annie Lööf, Hans Dalborg, Claes Dahlbäck, Helene Hellmark Knutsson, Magdalena Andersson, Mikael Damberg, Börje Ekholm, Anders Borg, Jan Carlzon, Fredrik Lundberg, Mona Sahlin, Carl-Henric Svanberg, Annika Falkengren, Leif Pagrotsky, Michael Treschow, Jan Björklund, Ulf Adelsohn, Lena Adelsohn Liljeroth, Pär Nuder, Hans Vestberg, Göran Hägglund, Fredrik Reinfeldt, Anna Kinberg Batra, Anders Wall, Carl Bennet, Hans Stråberg and others.

[17] Wallenberg was taken to his final resting place in the world's only Saab hearse, manufactured by the company that his father once was one of the founders of.