Fulton County Judge Scott McAfee found that state prosecutors did not have the authority to bring those charges, which related to the alleged filing of false documents in federal court.
McAfee allowed the remainder of the case to move forward, including eight charges against Trump. Trump and 14 co-defendants have pleaded not guilty to racketeering and other charges stemming from what prosecutors allege was a scheme to overturn Trump's narrow defeat in Georgia in the 2020 election.
The case has been on hold since June while a Georgia appeals court considers whether the lead prosecutor, Fulton County District Attorney Fani Willis, must be disqualified over alleged misconduct tied to a romantic relationship she had with a former top deputy.
Arguments in the appeals court are scheduled for December, meaning the case will not progress before the November 5 election when Trump stands against Democratic Vice President Kamala Harris.
A separate federal case Trump faced for his efforts to overturn his election defeat nationally has also been slowed dramatically by a US Supreme Court ruling that found that presidents have broad immunity from criminal prosecution.
Thursday's decision relates to allegations that Trump and his allies assembled a slate of fraudulent presidential electors and filed a civil lawsuit challenging the election results that contained false claims.
The ruling means that five of the original 13 criminal counts against Trump in the indictment obtained last year have now been tossed out. McAfee in March dismissed six other counts, including three against Trump.
Trump lawyer Steve Sadow said in a statement that the ruling showed that Trump and his legal team "have prevailed once again."
In a separate decision on Thursday, McAfee upheld the primary charge in the case, racketeering, which has been brought against all the defendants.
