The writer, who began a two-year stint as Children's Laureate in June, has beaten businesspeople and politicians to top the seventh annual edition of The Powerlist, which counts down "Britain's 100 most influential black people".
Blackman, whose works have included Pig-Heart Boy and her Noughts & Crosses series, is the first author to head the list, and follows figures such as Baroness Scotland, Baroness Amos and David Adjaye. The top 10 for 2014 also includes Mo Farah at number four, and Baroness Doreen Lawrence, director of the Stephen Lawrence Charitable Trust at number seven.
Blackman, who worked in computing before publishing the first of more than 60 books at the age of 28, said: "I am deeply honoured to be chosen as number one on the Powerlist.
"Highlighting so many black people in such diverse different spheres is such an inspiring thing. It challenges stereotypes and shows that many people are achieving great things. It's a fantastic showcase of the amazing success stories that often go unreported. It's a real honour to be among such company."
The figures chosen for their "ability to alter events and change lives", must be of African-Caribbean heritage, born or living in the UK.