Wallenberg became Vice CEO of the Stockholms Enskilda Bank and a member of its board of directors in 1920 He was CEO until 1946 and then vice chairman of the board from 1946 to 1950 and chairman from 1950 to 1969. Wallenberg was in the early 1930s a board member of Vikmanshytte bruks AB, AB Diligentia,
Stockholms Rederi AB Svea, Stockholm-Västerås-Bergslagens Nya Jernvägsaktiebolag, Göta kanalbolag AB,
Investor AB, Wedevågs bruks AB, Svenska obligationskreditaktiebolaget AB, International Bk te in
Amsterdam and Società Esercizi Telefonici. In the late 1930s, Wallenberg was chairman of the board of
Svenska Tändsticks AB and board member of AB Diligentia, AB Obligations-Intressenter,
AB Separator,
AB Svenska Kullagerfabriken (SKF), Göta kanalbolag, Stockholm-Västerås-Bergslagens Nya Jernvägsaktiebolag, August Stenman AB, Svenska Personal-Pensionskassan, Svenska obligationskreditaktiebolaget AB, Wikmanshytte Bruks AB and Kreutoll Realization Co. He was also voting trustee in the International Match Realization Co. Ltd and was on the board of the
National Institute of Economic Research (from 1937) and of the
Maritime Museum in Stockholm (from 1939). Wallenberg was in the mid-1940s chairman of the board of Svenska Tändsticks AB, Svenska Ostasiatiska Kompaniet,
AB International Harvester Co. and August Stenman AB. and
Stora Kopparbergs Bergslags AB. Wallenberg was in the mid-1950s chairman of the board of Förvaltnings AB Providentia, AB Investor, AB International Harvester Co., Kemi-Intressen AB,
Nordiska Kompaniet (NK), Stora Kopparbergs Bergslags AB, Svenska Diamantbergborrnings AB, AB Svenska Kullagerfabriken, AB Svenska Ostasiatiska Kompaniet, Svenska Tändsticks AB and Wifstavarfs AB, the
Royal Swedish Yacht Club (KSSS). He was vice chairman of the board of Försäkrings AB Skandia-Freja, Göta kanalbolag and Orkla Gruve AB. Wallenberg was board member of AB Iggesunds Bruk, Kopparfors AB, AB Separator, August Stenman AB, Wikmanshytte Bruks AB, the
Nobel Foundation and the
Knut and Alice Wallenberg Foundation. In the late 1960s, Wallenberg was also chairman of the board of Bergvik & Ala AB. He was a board member of AB Iggesunds Bruk, Nordiska Kompaniet (NK),
Skandia, Göta kanalbolag, Wikmanshytte Bruks AB, the Nobel Foundation (from 1952), the Knut and Alice Wallenberg Foundation and King Gustaf V's Jubilee Fund. Wallenberg was treasurer of the Cancer Society in Stockholm. ==Personal life==