Oswald Jürgen Grübel (born November 23, 1943) is a German banker who was the group chief executive officer of Swiss bank UBS AG from 26 February 2009 until his sudden resignation on the 24 September 2011 in the wake of the 2011 UBS rogue trader scandal.

Grübel began his career at a White Weld & Co. joint venture with Credit Suisse in the 1970s.

After he retired in May 2007, he still held a board position at the Winterthur Group insurance company (a part of AXA) from 2007 until 2009.

As chairman of the CEO position at UBS he made a promise that he will lead the bank back to the profit zone of 15 billion USDS in 2014.

Earlier he had been under pressure having assumed the full responsibility for the USD 2.3 billion loss resulting from the 2011 UBS rogue trader scandal.