In 1968, Maclennan married Helen Noyes (née Cutter), daughter of Justice Richard Ammi Cutter of the Massachusetts Supreme Judicial Court. As Maclennan's spouse she was Lady Maclennan of Rogart. She had one son from a previous marriage, and a son and a daughter with Maclennan. Maclennan died at his home in the
City of Westminster on 18 January 2020, at age 83. == References ==