Sir William Ivor Jennings, KBE, QC (Sinhala:ශ්‍රිමත් අයිවර් ජෙන්නින්ග්ස්) (16 May 1903 – 19 December 1965) was a British lawyer and academic. He was a prominent educator who served as the Vice Chancellor of University of Cambridge (1961–63) and University of Ceylon (1942–55).