|This article may be expanded with text translated from the corresponding article in the Romanian Wikipedia. (September 2013)|
Popovici was born in Ruşii Mănăstioarei village of Suceava county. In 1908, while a high school student, he crossed the Austrian-Romanian border illegally, in order to see Nicolae Iorga who was visiting the town of Burdujeni. When World War I started, he went to Romania and enlisted in the Romanian Army, fighting until the end of the war.
Military dictator Ion Antonescu requested him to become mayor of Cernăuţi, but Popovici initially refused, unwilling to serve a fascist government. He changed his mind, however, based on advice from his friends. A few days after acceptance, he was ordered to create a ghetto for the Jews of Cernăuţi, but Popovici refused to accept that part of the city's population could be confined behind barbed wire fences. After long debates, the governor of the region accepted his point of view. Due to Popovici's defense of Jews, his political adversaries nicknamed him "jidovitul" ("the turned-Jewish").
In 1941, the new governor announced his decision that all the Jews of Cernăuţi must be deported to Transnistria. After talks with the governor, the latter agreed that Popovici would be allowed to nominate 200 Jews which were to be exempted. Unsatisfied with the modest concession, Traian Popovici tried reaching Antonescu himself, this time arguing that Jews were of capital importance to Cernăuţi's economy and requested a postponement until replacements could be found. As a result, he was allowed to expand the list, which covered 20,000 Jews in its final version.
He is honored by Israel's Yad Vashem memorial as one of the Righteous Among the Nations, an honour given to non-Jews who behaved with heroism in trying to save Jews from the genocide of the Holocaust.