Bruno started boxing aged nine and became the youngest amateur British champion at 18.
Born in Hammersmith, west London, he was made an MBE in 1990.
In 1995 he beat Oliver McCall to become the World Boxing Council Heavyweight Champion. The following year he retired.
He was nominated for the City of London award by former lord mayor of the City of London, alderman Alastair King, who served last year, and alderman Robert Howard.
Mr Howard said: “Frank Bruno has become an inspirational figure, not only for his hugely impressive achievements in the boxing ring but also for how he has spoken with admirable courage and candour about his mental health challenges.
“We are today recognising, perhaps even celebrating, his significant contribution to opening up these sensitive topics for discussion and reflection.”