Lewis Ryers Thompson (August 6, 1883–November 12, 1954) was an American physician who served as Assistant Surgeon General of the United States and as Director of the National Institutes of Health.

[4] When the Division of Scientific Research was merged with Hygienic Laboratory to form the NIH in 1930, Thompson was chosen to be the director of the consolidated agency.

[4] He oversaw the move of the NIH to its current site in Bethesda, Maryland, having been the primary mover behind securing funding for the first six buildings.

[3] With his old ally Thomas Parran, Thompson assisted in the establishment of the National Cancer Institute as part of the Public Health Service.

During World War II and its aftermath, he was chief of the Medical Division of the United States Strategic Bombing Survey in Japan.