Judge Michael Russo said a competency evaluation showed with "reasonable medical certainty" that Castro, 52, is capable of understanding the proceedings and assisting counsel.
The next pretrial hearing is July 24, and jury selection is tentatively scheduled to begin August 5.
"So consistent with the statute where there is presumption of competency and consistent with the report done by our experts which the court is accepting as evidence for purposes of this hearing, the court finds Mr. Castro is competent to proceed in this matter, to assist council and to stand trial," the judge said.
Neither the defense nor the state presented witnesses at the hearing and both agreed that Castro is competent to stand trial.
Castro, clad in an orange prison suit, sat in the court during the hearing, his head lowered and eyes sometimes closed. He answered questions directly, telling the judge he understood the proceedings.
The suspect was evaluated by two psychiatrists. The competency report is sealed, so it won't be publicly available.
In another issue, Castro wants his children to be able to visit him in jail, but the judge said he won't let the minor children visit because it would be inappropriate.
Prosecutors confirmed in court they intend to seek a superseding indictment, meaning they will present the case again to the grand jury from scratch. It is unclear whether that will affect the August trial date.
Castro is accused of holding the women in his Cleveland home. He faces 329 counts, including one count of aggravated murder for allegedly causing the unlawful termination of a pregnancy.