Frank Humphrey Sinkler Jennings was an English documentary filmmaker and one of the founders of the Mass Observation organisation. Jennings was described by film critic and director Lindsay Anderson in 1954 as "the only real poet that British cinema has yet produced".

Mass-Observation is a United Kingdom social research project; originally the name of an organisation which ran from 1937 to the mid-1960s, and was revived in 1981 at the University of Sussex.