In Israel, he’s already known as “Bibi’s Brain:’’ Prime Minister Benjamin “Bibi” Netanyahu’s master strategist.

But Ron Dermer, 42-year-old Miami Beach native, now Israeli citizen — the son of one Miami Beach mayor and brother of another — could soon add an official title to his resume: Mr. Ambassador.

Dermer is reportedly Netanyahu’s choice for Israeli ambassador to the United States to replace Michael Oren, who plans to step down in the spring after four years.

A political conservative with close ties to powerful American Republicans, Dermer would become Israel’s top diplomat in the United States, a position requiring the ability to represent his country’s interests across U.S. party lines.

Netanyahu’s office hasn’t commented on the reports. A spokesman for the Israeli consulate in Miami could not confirm the possible appointment, nor could Dermer’s older brother, former Mayor David Dermer, who called any speculation “premature.’’ A spokesman for the Israeli embassy in Washington told the Jewish Telegraphic Agency that the rumor was “baseless.’’ In any case, the Netanyahu government would have to survive a Parliamentary election later this month.

An Oxford-educated scholar-athlete who holds degrees in finance and management from the University of Pennsylvania’s prestigious Wharton School, and who quarterbacked Israel’s flag football World Cup team three times, Dermer is known as smart, polished, and so competitive that “he wouldn’t let a 3-year-old beat him at Ping-Pong,” friend Tom Rose, former Jerusalem Post publisher, once said in an interview.

Dermer “cannot abide anybody being better at him than anything, particularly physically,” Rose said.

The mere speculation that Dermer might be named seemed to thrill South Florida politicians from both parties.

“It’s wonderful — one of our own being Israel’s ambassador to the U.S.,” said U.S. Rep. Ileana Ros-Lehtinen, R-Miami, who knows Dermer. “It is just terrific. He is American as apple pie yet Israeli at heart as well. It is a good fit. He is very much a proud Miami Beach guy — very proud of his hometown.”

U.S. Rep. Debbie Wasserman Schultz, the Democratic National Committee chairwoman, said she met Dermer as part of a Congressional delegation to Israel in 2010. Dermer was the staff person who sat next to Netanyahu as they discussed the peace process, she said.

“It was just neat to see someone reach the heights he has — he hails from South Florida and comes from a political family here,” she said. “It made the connection and conversations with the prime minister really just that much more warm and intimate.”

U.S. Rep. Ron Klein, D-Boca Raton, said that the job Dermer holds now — working behind the scenes and with the White House — is very different from being ambassador to the United States, which would require him to directly address Americans in speeches and through the media.

“Ambassador to the U.S. is the most high-profile diplomatic position in Israel,” Klein said. “It requires a tremendous amount of savvy and style that Americans can relate to.”