Leslie Lars Iversen CBE FRS MAE (31 October 1937 – 30 July 2020), was a British pharmacologist, known for his work on the neurochemistry of neurotransmission.

[1] Of Norwegian descent, Iversen attended Hele's School, Exeter,[2][3][4] and Trinity College, Cambridge, where he graduated with a BA in natural sciences and a PhD in pharmacology.

Between 1982 and 1995 he worked as Director of the Merck, Sharp & Dohme Neuroscience Research Centre.

[6] In 2000, Iversen published the book The Science of Marijuana by Oxford University Press, Inc.[7] In 2010 he was accused of plagiarism.

[11] He was appointed a Commander of the Order of the British Empire (CBE) in the 2013 New Year Honours, "for services to pharmacology".