South African security police today ordered the banning for five years of white student leader Sammy Adelman, who had publicly sided with black students in recent antiapartheid protests.

Adelman, 25, president of the student council at the University of Witwatersrand, is prohibited by the decree from meeting with more than one person at a time or speaking in public and may not be quoted in the press.

Adelman had invited actress Jane Fonda and her politician husband Tom Hayden, who are on a tour of southern and eastern African countries, to speak at the university on academic freedom, but South African authorities denied them visas earlier this week. Reached by telephone at Johannesburg's Jan Smuts Airport today, Hayden said they were angered by Adelman's arrest and thought it might have been "an official act of retribution . . . for inviting us to speak in South Africa."

They said they will lobby against the Reagan administration's policy of befriending South Africa when they return to the United States. "Not to let us in is unbelievable," Hayden said. "That is not the behavior of a friend [of the United States]. . . We are not going to let Sammy Adelman become a nonperson."

Hayden and Fonda were under surveillance of security police at the airport after arriving there yesterday in transit to Lesotho, a black-ruled kingdom surrounded by South Africa. They said they were refused permission to go to a hotel and spent the night in the transit lounge.

Banning is a common retaliation against outspoken critics of the government's racial policies, and 162 persons are currently under ban, which is not subject to judicial appeal.

Witwatersrand recently has been one of the centers of antigovernment rallies. At one of the meetings the South African flag was burned. Adelman's banning, for which no official reason was given, is probably related more to his campus activities than to his invitation to Hayden.