The City Club of Portland was founded in 1916 in Portland, Oregon. The group began holding weekly lunch meetings, which would later become known as Friday Forums. The proceedings of these meetings were broadcast on radio starting in 1928. In the early 21st century, Oregon Public Broadcasting Radio and Portland Community Media TV broadcast the Friday Forums.

The City Club conducts research studies examining matters concerning Portland, Oregon, and potential improvement projects for the Portland metropolitan area. These studies have sometimes had considerable influence on public policy, such as the establishment of Portland's Forest Park. The club's 1955 report on water fluoridation gained national attention, although in spite of the club's recommendations, Portland voters rejected several proposals to fluoridate the city's drinking water made during the 20th and early 21st centuries. In 1984, the City Club caused controversy when it recommended that prostitution be legalized in Portland.

Originally an exclusively male organization which could only be joined by invitation, since 1988 anyone over the age of 17 is permitted to become a member of the City Club. The Club's first African-American member, DeNorval Unthank, joined in 1943. Women were permitted to join starting in 1973.

As of 2019, the club's offices are in the Pittock Block in downtown Portland, Oregon.