A Fairfax Circuit Court judge and an Arlington circuit judge were endorsed by the Fairfax Bar Association yesterday as Northern Virginia nominees to the state's recently created intermediate appellate court.

Judge Barbara Keenan, 33, one of only two women in Virginia who sits as a circuit court judge, was endorsed for the controversial nine-member appellate court along with Judge Charles Duff, 58, of the Arlington Circuit Court, according to Jerry M. Phillips, president of the bar association.

Keenan and Duff, along with candidates endorsed by other bar associations throughout the state, will be reviewed by their respective local legislative delegations.

The full General Assembly will elect the members of the new court, which is scheduled to come into being Jan. 1, 1985. The court will serve as an intermediate court, screening cases appealed from local circuit courts to the Virginia Supreme Court. Proponents of the new court said it will help reduce the caseload of the overburdened Supreme Court, while opponents said it was an expensive, unnecessary political creation.

The Fairfax Bar Association yesterday also endorsed three candidates for the seat on the Fairfax Circuit Court that will be vacated Oct. 1 when Judge Burch Millsap retires.

The three candidates, whose names will be submitted to the local legislative delegation, are Thomas A. Fortkort, 49, chief judge of the Fairfax Juvenile and Domestic Relations Court; John J. Sabourin Jr., 38, a member of the Fairfax County law firm of Hazel, Beckhorn and Hanes, and Jack B. Stevens, 51, of the Alexandria law firm of Stevens, Cake, Rhoades and Rideout.

They were selected by a bar association screening committee from a list of eight nominees.

Local legislators will select one of the three candidates and submit his name to Gov. Charles S. Robb for consideration. The legislative delegation and the bar association have asked Robb to name an interim judge until the General Assembly can elect a permanent replacement during its 1984 session.

The local legislative delegation is not bound to support any of the bar association's endorsements. But Northern Virginia legislators traditionally have selected judicial candidates from among the bar recommendations.

The recommendations for the appellate court and the circuit court seat were announced yesterday after two days of voting by the bar association's general membership, Phillips said.