Simon was awarded a number of awards and honorary doctorates: 
* 1972 Chemistry Award of the Göttingen Academy of Sciences and Humanities
* 1985 Wilhelm Klemm Award of the Society of German Chemists
* 1987 Otto Bayer Award
* 1990 Gottfried Wilhelm Leibniz Prize 
* 1998 Dr. rer.nat. h.c. of Technical University Dresden
* 1998 Dr. rer.nat. h.c. of University (TH) Karlsruhe
* 1998 Centenary Prize, Royal Society of Chemistry
* 2001 Dr. phil. h.c. of Stockholm University
* 2002 Dr. h.c. of Université de Rennes I
* 2004 Sir Nevill Mott Lecture, University of Loughborough
* 2004 Liebig-Denkmünze of the Society of German Chemists
* 2011 Terrae Rarae Award
He is also a member of several academies of sciences:
* 1989 Member of the Academy of Sciences and Literature Mainz (Corresponding Member since 1994)
* 1990 Member of the Heidelberg Academy of Sciences and Humanities
* 1990 Member of the Academia Europaea
* 1992 Member of  the Russian Academy of Sciences
* 1998 Member of the Academy of Sciences Leopoldina
* 1998 Foreign Member of the French Academy of Sciences
* 2003 Honorary Fellow of the Chemical Research Society of India