In the campaign for human rights and justice in apartheid South Africa, black American civil rights leaders were instrumental. One was Leon H. Sullivan, who enunciated the “Sullivan Principles” guiding multinational firms toward treating blacks fairly while doing business in South Africa. Why, then, is the Leon H. Sullivan Foundation today celebrating the exploits of a brutal African tyrant?

On Aug. 20, a plane-load of lobbyists, civil rights leaders, entertainers and former government officials will land in the West African nation of Equatorial Guinea for the Sullivan Summit IX. The summit’s stated objective is to “create an atmosphere of open dialogue about the state of human rights and the interconnected issues of modern Africa.” Seldom has so much dishonesty fit into one sentence.

Equatorial Guinea is home to Africa’s longest-ruling dictator, Teodoro Obiang Nguema, who seized power in a military coup by executing his uncle 33 years ago. Freedom House ranks the country among the “worst of the worst” human-rights abusers, along with North Korea, Syria and Somalia. Yet the Sullivan Foundation is celebrating its Obiang-hosted summit as a milestone for human rights, part of its “unwavering commitment to democratic ideals.”

According to the agenda posted online, summit attendees will lounge at a five-star resort for a week discussing human rights and economic development, all between black-tie dinners and champagne. They may toast to the petroleum-rich country’s staggering per capita income of $36,515 (according to the World Bank), but outside the resort the people of Equatorial Guinea will continue to toil in poverty. Sixty percent live on less than $1 a day, the majority don’t have access to clean water or electricity, and nearly one in eight children die before their fifth birthday.

Since his 1979 coup, Mr. Obiang has rigged every election to give himself more than 95% of the vote. He has criminalized dissent, tortured or disappeared his opponents, and killed tens of thousands (as documented by historian Randall Fegley, among many others). Under his iron first, Mr. Obiang siphons billions of dollars in oil revenues into his family coffers. Still the Sullivan Foundation’s marketing materials praise him for a “tremendous emphasis on social development and good governance.”

Nor is this month’s summit the first time the Sullivan Foundation has cozied up to Mr. Obiang. Last December it bestowed on him its “Beacon for Africa” award for “exemplary contributions to improving the lives of Africa’s most vulnerable citizens.” When news of the award first leaked, the foundation initially denied that Mr. Obiang was honored, tweeting that a horrible mistake had been made. It then pretended that it was honoring only the rotating presidency of the African Union, which happened to be held at the time by Mr. Obiang.

It doesn’t end there. In June, foundation President and CEO Hope Sullivan Masters—daughter of Leon Sullivan, who died in 2001—hosted a private reception for Mr. Obiang at her Maryland mansion. As for criticism of the upcoming summit, Ms. Masters wrote on her foundation’s website this week that it is “yellow journalism,” “salacious and blasphemous.” She added: “If these critics wish, they are more than welcome to attend the Summit and see for themselves the advancements made by President Obiang for his country.”

The dictator has made a practice of linking himself to international organizations. This year he paid Unesco, the U.N.’s cultural and educational arm, $3 million to establish the Unesco-Equatorial Guinea International Prize for Research in the Life Sciences. Unesco’s executive board agreed to sponsor the prize over objections from its own lawyers, the U.S. government and others.

The Sullivan Foundation’s chairman is Andrew Young, a former mayor of Atlanta and U.S. ambassador to the U.N., and its board of directors includes former President Bill Clinton. If Messrs. Young, Clinton and their colleagues want to help Africa and Equatorial Guinea, they should be on the side of the people, not the dictators. They might support EG Justice, which promotes human rights, rule of law, transparency and civic participation in Equatorial Guinea. (EG Justice is based in the U.S. because human-rights groups can’t operate in Equatorial Guinea.) Perhaps the Sullivan Foundation could host gatherings for EG Justice’s founder, Tutu Alicante, instead of the murderous dictator who has long immiserated his country.

The summit begins in a few days without any hope of achieving its supposed objectives: “to protect the infirmed, the poor, the defenseless, and the isolated,” “to explore how the public and the private sectors can manage a changing society while not leaving our most vulnerable members behind,” and to “drive a world economy that will benefit all.” Gathering under Mr. Obiang’s banner will undermine those goals in Equatorial Guinea by lending support to a repressive, exploitative system that benefits an elite few who remain in power through crime and violence. It is an appalling swindle.