The Salvator Mundi is a painted wooden panel depicting Christ. It was exhibited in 2011 as an original work by Leonardo da Vinci, but the attribution has been controversial, with some scholars describing da Vinci as a contributor but not the main artist. Kemp's research supported its attribution to da Vinci. He said that as soon as he viewed the painting, he recognised the presence and "uncanny strangeness" of da Vinci's works. The painting was sold in 2017, setting a new record for the most expensive painting ever sold at public auction. In a 2019 book, Kemp identifies symbolism in the painting that is familiar from da Vinci's other religious paintings. He is interviewed in the 2021 documentary about the work, The Lost Leonardo.
