Awarded by RIBA and personally approved by the Queen, the Royal Gold Medal recognises those who have dedicated their lives to the "advancement of architecture".
"It's incredibly humbling and a great honour to have my peers recognise the work I have developed with my team and its contribution to the field over the past 25 years," said Adjaye, who founded Adjaye Associates in 2000.
"Architecture, for me, has always been about the creation of beauty to edify all peoples around the world equally and to contribute to the evolution of the craft," he added.
"The social impact of this discipline has been and will continue to be the guiding force in the experimentation that informs my practice."
Adjaye, who was knighted in 2017 for his services to architecture, is the architect of projects including the Smithsonian National Museum of African American History and Culture and the Ideas Store Whitechapel in London.
Adjaye Associates is currently working on the National Cathedral of Ghana in Accra, where the practice has offices.
"David's contribution to architecture and design globally is already astounding, and I am excited that we have so much more of it to look forward to," said RIBA president Alan Jones.
"At every scale, from private homes to major arts centres, one senses David Adjaye's careful consideration of the creative and enriching power of architecture," added Jones.
"I believe his both practising and teaching in schools of architecture has significantly enriched his work. His artistic and social vision has created public projects that perfectly demonstrate the civic potential of architecture – fostering empathy, identity and pride."
Adjaye made his name with residential projects such as Hackney's Dirty House. His housing projects range from Sugar Hill, an affordable housing development in Harlem, to a 66-storey skyscraper sete to be built in Manhatten.
The architect has been vocal about the power of architecture to counteract dangerous false narratives around white supremacy and climate change.
"I think it's important for architecture to be one of the devices that's not about propagating fictions about history and how history is written," Adjaye told Dezeen.
"When your monuments contradict the narratives that have been projected, it breaks the illusion."
Adjaye has designed monuments dedicated to important black figures, including a concrete memorial pavilion for trumpeter and anti-apartheid activist Hugh Masekela in Johannesburg. He built the Stephen Lawrence Centre in London, an educational facility set up in the memory of a young black aspiring architect murdered in a racially motivated attack.
He is also currently working on a memorial in Brixton to Cherry Groce, a black woman who was shot in her home by police in a botched raid in 1985.
Last year the Royal Gold Medal was awarded to Grafton Architects, the practice founded by Yvonne Farrell and Shelley McNamara, making them first all-woman pair to win in the awards' history.