The nomination was a formality as he had already won the majority of the more than 3,900 delegates back in June.
The roll call came on Day 2 of the mostly virtual Democratic National Convention aimed at celebrating the party's candidate and welcoming independents and frustrated Republicans into their political movement to droust Trump from the White House.
The proceedings included a series of presentations by party leaders past and future who unleashed their own arguments against the White House incumbent and urged voters to rally around Biden.
The lineup featured 95-year-old president Jimmy Carter, who served one term from 1977, and 1990s commander-in-chief Bill Clinton, who warned that the Trump White House is swirling with chaos instead of the competence necessary to address the nation's crises.
"At a time like this, the Oval Office should be a command center. Instead, it's a storm center. There's only chaos," Clinton said.
"Just one thing never changes — his determination to deny responsibility and shift the blame," Clinton said. "The buck never stops there."
The night's emotional underpinning was delivered by Jill Biden, who closed out the night with a compelling profile of the man she married in 1977.
The educator from Pennsylvania delivered a personal, high-stakes prime-time testimonial describing how the personal tragedy of the death of Biden's first wife and daughter in a 1972 car crash has shaped him.