Jürgen Heinz Lothar Grobler OBE (born 31 July 1946, Magdeburg) is a German rowing coach, formerly the Olympic team coach of East Germany and later of Great Britain. He has coached crews to medals at every Olympics since 1972 with the exception of the 1984 Games due to the boycott by Eastern Bloc countries.
Having studied sports science at Leipzig University, he returned to his local rowing club in Magdeburg and first attracted attention by coaching Wolfgang Guldenpfennig to the bronze medal in the 1972 Olympics. He then moved on to coach both the quadruple scull and coxless pairs who won gold at the 1976 Summer Olympics. The coxless pair of Bernd and Jörg Landvoigt also went on to triumph at the 1980 Summer Olympics under Grobler's guidance. From 1980 to 1990 he was chief coach of the East German women's rowing team.
When Germany was reunited and the East German national sports administration collapsed in 1991, Gröbler moved to Britain where he was employed by Leander Club and the Amateur Rowing Association. Controversy surrounded the appointment, given the suspicions that drug use had been rife in East German sports and that any senior coach would have been involved or had knowledge of the drugs programme. In an interview in 1998 he admitted that he had "difficulties" with the thought that drug taking may have caused medical problems for rowers, and that he had given "snippets" of information to the Stasi, the East German security organisation. Steve Redgrave defended him, blaming the East German system for the drug use, rather than Grobler personally, in keeping with Grobler's own statement that "I have to live with what went on in East Germany. I was born in the wrong place. It was not possible to walk away."