Mayor Bloomberg is expected to pay tribute to one of his legendary predecessors when he declares December 11 to be “Fiorello La Guardia Day.”

Tomorrow’s event will celebrate the former mayor’s 125th birthday and feature a ceremony during which two recipients, chosen because they exemplify his finer traits, are awarded “La Guardia Leadership Medals.”

Although the mayor will not be in attendance for the festivities at Gracie Mansion, a granddaughter of Mayor La Guardia who is a co-founder of the nonprofit La Guardia Foundation, Katherine La Guardia, said Mr. Bloomberg and his staff were “wonderfully supportive.”

The Bronx-born son of Italian and Jewish parents, La Guardia served three terms as the city’s mayor. In addition to major public works projects, anti-corruption reforms, and the construction of the airport that bears his name, La Guardia was known for his international work. He was an early and outspoken opponent of Hitler and took a position with the U.N. after leaving office, directing relief operations in post-World War II Europe.

Dr. La Guardia said yesterday that she sees in Mr. Bloomberg her grandfather’s dedication to global issues, and to improving the city. Her foundation has endorsed the mayor’s 2030 sustainability plan. “To us it is carrying on the vision of Mayor La Guardia in a way that no other mayor has really articulated as well,” Dr. La Guardia said of the mayor’s plan.

“Much of what Mayor La Guardia initiated was not only reforms in the way the city of New York treated people,” she said. “He embarked upon a visionary beautification program for the city of New York, building parks, infrastructure — subways that would allow people to travel and enjoy a beautiful New York.”

“We see Mayor Bloomberg as carrying on that vision,” she said.