Virginia Gov. John N. Dalton has appointed the first blacks to the boards of visitors at the University of Virginia and the College of William and Mary, two of the most sought-after political appointments in the state.

In keeping a campaign pledge to place more blacks on state boards and commissions, Dalton named Frank S. Royal, a Richmond doctor, to the U-Va. board and Henry T. Tucker Jr., a Chicago bank officer, to the board at William and Mary.

The appointment of the two blacks comes at a time when the state is under pressure from the federal government to appoint more blacks to the governing boards of the state-supported colleges and universities.

"I'm elated to have the opportunity to serve," the 38-year-old Royal said yesterday. Royal was cochairman of the governor's statewide election campaign.

A graduate of Virginia Union University in Richmond and Meharry Medical College in Nashville, Tenn., Royal had been asked - but declined - to serve in Dalton's cabinet as the state's secretary of human resources.

Dalton subsequently appointed Jean L. Harris to the human resources post, making her the first woman and first black to fill a high-level policy-making state government position in Virginia's history.

Tucker, 27, a graduate of William and Mary and the University of Virginia Law School. He is a trust officer with the Continental Bank of Chicago.

In announcing his appointments to the boards on Monday and yesterday, Dalton also named Stephen C. Mahan of Fairfax to the U.Va. board and Horace (Chip) Mann III of Richmond to the William and Mary board.

Mahan and Mann, both of whom are active in the Linwood Holton for Senate campaign, are 1977 graduates of the colleges on whose boards they serve.

This is the first time that a recent graduate has served on the William and Mary board.

Among other people, Dalton also reappointed two Northern Virginia women to the boards: Virginia Holton of McLean, wife of former governor Holton, to the U.Va. board, and Pamela Pauly Chinnis of Alexandria to the William and Mary board.