Jason Nissen, who teaches math at Frank Sinatra School of the Arts in Queens, gave the tickets to his students for $30 each to the Sept. 24 concert that was attended by more than 85,000 fans.
The second-year teacher denied that he sold the tickets for a profit, insisting that a friend who works for concert sponsor America Online sold him 19 extra tickets.
Nissen received a letter of reprimand from Eliot Salow, principal of Frank Sinatra HS, who called the math teacher's actions "inappropriate."
Mayor Michael Bloomberg was blunter.
"I thought it was a disgrace," the mayor told the Daily News. "This is not the kind of guy you want in our school system. Period."
The News reported that the city's special schools investigator was looking into the alleged ticket scalping.
Officials said that Nissen was charged last year with scapling tickets outside the U.S. Open. He pleaded guilty last month to disorderly conduct and fined $100.