Ofield Dukes, a prominent Washington public relations executive who represented major civil rights figures and entertainers and who helped focus support for a national holiday honoring the Rev. Martin Luther King Jr., died Dec. 7 at a hospital in Detroit. He was 79.

Several months ago, Mr. Dukes retired and returned to live in his home town, Detroit. His sister Betty Hayden said he died of multiple myeloma, a form of bone cancer.

After working in the administration of President Lyndon B. Johnson, Mr. Dukes opened his public relations agency, Ofield Dukes & Associates, in 1969. His first client was Motown Records.

Capitalizing on his political connections and Washington’s stature as a crossroads of black leaders, Mr. Dukes soon became one of the country’s leading African American public relations professionals.

He consulted with every Democratic presidential candidate since 1968, organized the first dinner of the Congressional Black Caucus in 1972, and counted Coretta Scott King, Stevie Wonder, Diana Ross, Rep. Charles B. Rangel (D-N.Y.), “Roots” author Alex Haley and boxing promoter Don King among his clients. Mr. Dukes was among the first African American members of the Democratic National Committee’s finance committee.

“Ofield was both a communications guru and someone who believed in equal opportunity for all,” DNC official Donna Brazile said Friday. “He was an adviser, a mentor, but most of all a writer who believed that we must all tell our story and tell it again and again.”

In 1976, The Washington Post named Mr. Dukes “one of the top public relations persuaders in the city.”

He later did work for many big-name clients, including Lever Brothers, Anheuser-Busch, CBS Records, AT&T, the National Bankers Association, the National Education Association and the Treasury Department. He represented several foreign countries, including Ghana and Liberia; participated in international trade missions; and helped rally opposition to the apartheid regime of South Africa.

“Besides being a black public relations firm,” Mr. Dukes told The Post in 1970, “we know Washington, we know the political scene nationally, we know the black leadership nationally and we know the leadership people in the new nations of Africa.”

At his company’s peak, in the late 1970s, Mr. Dukes had more than a dozen employees and annual billings of more than $1 million.

In 1981, while working with Wonder, he had a key role in planning a march on Washington that helped lead to King’s birthday being declared a national holiday.

Three decades later, Mr. Dukes was present when a memorial to King was put in place on the Mall.

“It’s almost like a miracle,” he told The Post. “It’s just unbelievable and incredible to have this type of symbol of an African American civil rights leader.”

Ofield Dukes was born Aug. 8, 1932, in Rutledge, Ala., and moved as a child to Detroit. He served in the Army during the Korean War and was a 1958 journalism graduate of Wayne State University.

He was news director for a Detroit radio station for three years, then became a writer for the Michigan Chronicle, a black-oriented newspaper in Detroit.

He came to Washington in 1964 as deputy director of public affairs for the Office of Equal Employment Opportunity. From 1966 to 1968, he was a communications adviser to Vice President Hubert H. Humphrey.

Mr. Dukes served on the board of the Martin Luther King Jr. Center for Nonviolent Social Change and was a founding member of the Congressional Black Caucus Foundation. In 2001, he became the first African American to win the Public Relations Society of America’s highest honor, the Gold Anvil Award. He was named to several PR halls of fame.

In 1981, Mr. Dukes launched the Washington North Star, a short-lived newspaper aimed at black readers.

As an adviser to the Congressional Black Caucus, Mr. Dukes worked closely with Rep. Charles Diggs (D-Mich.). He testified at a 1978 trial in which Diggs was convicted of mail fraud and diverting public money to his own use. Mr. Dukes was not charged with any wrongdoing.

Widely known in cultural circles, he was once described by Ebony magazine as “one of the most popular bachelors in Washington.” He often took friends to theatrical productions and was a member of the board of the old D.C. Black Repertory Theater.

A longtime adjunct professor at Howard University and later American University, Mr. Dukes was credited with guiding hundreds of students into public relations.

His marriages to Rosa Trapp and Elaine Sutton ended in divorce.

Survivors include a daughter from his first marriage, Roxi Victorian of Baton Rouge; three sisters; and a grandson.

After helping plan Johnson’s 1965 inauguration, Mr. Dukes became adept at organizing celebrations. He helped coordinate the 1975 inaugural festivities when the District’s first officials elected under home rule took office.

With only 48 hours’ notice, he organized a downtown parade to celebrate the Washington Bullets’ 1978 NBA championship victory. More than 100,000 jubilant spectators turned out.