[7] In May 2020, amid nationwide protests over the murder of George Floyd, Ossé became a prominent Black Lives Matter organizer and co-founded the activist collective Warriors in the Garden.

[8] On Juneteenth 2020, Ossé announced his 2021 campaign to succeed term-limited Councilman Robert Cornegy in the 36th district of the New York City Council.

[10][11] With endorsements from the Working Families Party and Congresswoman Alexandria Ocasio-Cortez's Courage to Change PAC, Ossé was seen as the furthest-left candidate in a field that also included district leader Henry Butler, local political operative Tahirah Moore, and pastor Robert Waterman.

[19] Ossé faced minimal opposition in the November general election, and won easily, becoming the council's youngest ever member.

His grandfather was Teddy Vann, a music producer who grew up in Brooklyn’s Bensonhurst neighborhood and won a Grammy working with his longtime protege Luther Vandross.