Sten Yngve Dennis Lagergren (6 May 1876 – 4 April 1922) was a Swedish physical chemist known for his fundamental findings in adsorption kinetics.

In 2018, 120 years after its publication, the paper was cited more than 800 times according to Clarivate Analytics' Web of Science, making its total number of citation above 6000.

In his perennial 1898 paper, Lagergren formulated a so-called pseudo-first-order model for adsorption kinetics based on an extensive body of experimental measurements.

In 1900, Wilhelm Ostwald (Nobel Prize winner in Chemistry in 1909) wrote an unusually extensive review of the paper in his Zeitschrift für physikalische Chemie.

The use of Lagergren's model gained a new impetus in the beginning of the 21st century largely with the advent of sorption-based technologies of water desalination.