Knut Agathon Wallenberg RoKKMO (19 May 1853 – 1 June 1938) was a Swedish banker and politician, he was also a Knight of the Order of the Seraphim.

Together with his wife, he created Knut and Alice Wallenberg Foundation, which is one of the main contributors to the private university Stockholm School of Economics.

In 1874 Wallenberg was commissioned as a naval officer and became Acting Sub-Lieutenant (Underlöjtnant) in the Swedish Navy the same year and joined the board of Stockholms Enskilda Bank.

In many respects his father's spiritual heir, the company led by him became one of Sweden's foremost, which mediated the taking up of large government loans and other significant deals.

He was also the driving force for many in the economic field, including in the creation of the residential community Saltsjöbaden near Stockholm and the railways connecting these places.