Ivan Earnest Allen Jr. (March 15, 1911 – July 2, 2003) was an American businessman who served two terms as the 51st mayor of Atlanta, during the Civil Rights Movement of the 1960s.

Allen took the helm of the Ivan Allen Company, his father's office supply business, in 1946 and within three years had the company bringing in annual revenues of several millions of dollars. In 1961, he authored a white paper for revitalizing Atlanta. It was adopted by the Atlanta Chamber of Commerce and became the Six Point Forward Atlanta program. This plan would become his roadmap as mayor for creating an economic surge that established the infrastructure, business, education, arts, sports, and international presence that are the foundations for modern Atlanta. Allen was a founding member of Atlanta's influential Commerce Club, which he chaired until his death in 2003. He became president of the city Chamber of Commerce in 1961 and during this same year ran for mayor, defeating the staunch segregationist, Lester Maddox.

Convinced that the South could never thrive economically under segregation, Allen supported the demands of African Americans for their accommodation at public facilities. On his first day in office, he ordered the removal of all "white" and "colored" signs from facilities in city hall. Racial alliances forged by Allen with Martin Luther King Jr. and others in the African American community, along with his advocacy for the public accommodation of African Americans in the white community, allowed Allen to guide Atlanta through the turbulence of racial integration without the violence that occurred in many southern cities. In a key address to the public, he asked Atlantans to eliminate racial segregation and in doing so, to set an example to inspire "all the world". At the behest of President John F. Kennedy, Allen testified before Congress on behalf of what became the Civil Rights Act of 1964. He was the only white southern politician of significance to do so. After his testimony, Allen and his family were under death threats and required police protection for a year.

Ivan Earnest Allen Jr. was born in Atlanta on March 15, 1911, the only son of Ivan Allen Sr. (1876–1968) and Irene Beaumont Allen (1889–1972). His father Allen Sr. was co-founder of the Ivan Allen Company (1900), an office supply and furniture store that, by 1925, had about fifty employees and was one of Atlanta's best-known businesses. Allen Sr. was also a founding member of the Atlanta Rotary Club, served as president of the new Atlanta Convention Bureau (1913–1917), president of the Atlanta Chamber of Commerce (1917), two years as senator in the Georgia state legislature (1918–1919), and was the treasurer of the Georgia Democratic Party in 1936. In an effort to attract northern capital to Atlanta, Allen Sr. headed the Atlanta chamber's "Forward Atlanta" booster campaign (1926–1929), a strategy that would lure almost 700 new businesses to Atlanta and serve to influence Allen Jr.'s future as a businessman and civic leader.

From an early age, Allen understood that his family was one of privilege. He began attending Boys High School in 1927, and was one of the few students to own a car. That same year, his father's name was published for the first time in the Social Cities Register, an annual list of elites in Richmond, Atlanta, Charleston, Savannah, and Augusta. He regularly attended the First Presbyterian Church of Atlanta with his parents, and would later serve as an elder for many years and an active member until his death.

Initially an indifferent student, Allen asserted himself during his last year at Boys High, earning a spot on the honor roll. In 1929, he enrolled in the School of Commerce at the Georgia Institute of Technology. During his first year at Georgia Tech, he was one of only five students in the student body of about two thousand to make straight A's. He graduated cum laude in 1933, with a Bachelor of Science in Commerce. While at Georgia Tech, he served as president of the student body, vice president of the Inter-Fraternity Council, cadet colonel of the ROTC, president of Omicron Delta Kappa, vice-president of ANAK, president of the Georgia Phi chapter of the Sigma Alpha Epsilon fraternity, was a member of the Honor Roll, and a member of the Dean's List.

At one point, he led a student protest against Governor Eugene Talmadge when the board of regents abolished the School of Commerce at Tech and moved it to the University of Georgia. During one summer as a college student he served as postmaster, strung tennis rackets, and worked as a counselor for young campers at Camp Greenbriar in Alderson, West Virginia. He was paid $500 and invested this money in Coca-Cola stock, of which he wrote was "my first investment and probably the greatest I ever made".

After graduating from Georgia Tech in 1933 during the depths of the Great Depression, Allen refused offers from other companies and began his lifetime of work in the family business, which was at the time called the Ivan Allen–Marshall Company. That summer, he worked in the basement of the business, learning from a black employee named Arthur Wright and earning $100 per month. At the time, the business consisted of one Atlanta store and grossed $196,000.