Roger Bruce Chaffee (February 15, 1935 – January 27, 1967) was a U.S. Navy pilot who became an American astronaut in the Apollo program.

He was born in Grand Rapids, Michigan, attended Illinois Institute of Technology and earned a B.S. in aeronautical engineering from Purdue University in 1957. He was married to Martha Horn Chaffee, and had two children, Sheryl and Stephen. Chaffee was an Eagle Scout.

He was a lieutenant commander in the Navy.

He was chosen in the third group of astronauts in 1963 and had made no spaceflights before being selected as lunar module pilot for the first Apollo program flight.

Chaffee died along with fellow astronauts Gus Grissom and Edward White in the Apollo 1 fire at Cape Kennedy.

The Chaffee crater on the far side of the Moon is named after him. The star Gamma Velorum was named "Regor" ("Roger" spelled backwards) in his honor. Roger B. Chaffee Elementary School, in Huntsville, Alabama, is named after him. Huntsville, also known as "Rocket City" is a large center for space technology and rocket development, and several of the schools are named after others who died in the space program.

The US Navy school at US Naval Air Station, Bermuda was named for him from 1970 to 1995. The school was closed with the hand-over of the base to the Bermudan government and is now named Clearwater Middle School. An artificial island in San Pedro Bay off Southern California, is also named for him.

Chaffee is remembered in his hometown where the Roger B. Chaffee Planetarium is named after him, as well as a street in an industrial park and the Roger B. Chaffee Scholarship, awarded annually to exceptional students in math and science in the Grand Rapids metropolitan area.

In the 1995 film Apollo 13 Chaffee was played by Reed Rudy. In the 1998 miniseries From the Earth to the Moon he was played by Ben Marley.