Sir James Fraser Stoddart (born 24 May 1942) is a British-Americanchemist who is Board of Trustees Professor of Chemistry and head of the Stoddart Mechanostereo Chemistry Group in the Department of Chemistry at Northwestern University in the United States.

He works in the area of supramolecular chemistry and nanotechnology. Stoddart has developed highly efficient syntheses of mechanically-interlocked molecular architectures such as molecular Borromean rings, catenanes and rotaxanes utilising molecular recognition and molecular self-assembly processes.

He has demonstrated that these topologies can be employed as molecular switches.

His group has even applied these structures in the fabrication of nanoelectronic devices and nanoelectromechanical systems (NEMS).

His efforts have been recognized by numerous awards including the 2007 King Faisal International Prize in Science.

He shared the Nobel Prize in Chemistry together with Ben Feringa and Jean-Pierre Sauvage in 2016 for the design and synthesis of molecular machines.

In 2017, he was elected as member of the European Academy of Engineering.