Mrs. Obama chose to celebrate her third annual College Signing Day at the Harlem Armory.
It's part of her 'Reach Higher' initiative.
The event brought out numerous celebrities, who all spoke about their college experiences and congratulated the students. Among the speakers were Robert De Niro, Tracee Ellis Ross, and Melissa McCarthy.
But the guests of honor were the more than 4,000 local high school seniors in attendance who have been accepted to college or a professional training program.
The first lady has hosted College Signing Day to celebrate high school seniors choosing to pursue higher education at a professional training program, a community college, or a four-year college or university.
"We all know that completing your education past high school is the most important thing you can do to reach your dreams, that's why we're here," she said. "So while you all might be in awe of us, let me tell you, we are in awe of you."
Previous events were held in San Antonio and Detroit.
Mrs. Obama also tweeted out photos of her and the president, and Vice President Joe Biden and his wife Jill, wearing shirts from their respective schools to show their college pride.
The first lady recounted her own experience starting at Princeton University where she said she initially felt out of her depth as a first generation college attendee until she reached out for support.
The event is catching on nationwide. Tuesday there were more than 1,000 signing day events across the country.
(The Associated Press contributed to this report.)