Accepting an award on the late star's behalf at a virtual Gotham Film Awards, Simone Ledward Boseman said he had been "the most honest person I've ever met".
"He didn't just stop at speaking the truth," she continued. "He actively searched for it in himself, in those around him and in the moment."
The Black Panther star died of cancer in August last year at the age of 43.
He was honoured with the Gotham Awards actor tribute prize.