Gary Miller (born September 15, 1958), better known by his stage name Dr. Know, is an American musician, who rose to prominence as the guitarist for the Washington D.C. hardcore punk band Bad Brains, who were critically acclaimed for their innovative musical style and are regarded as one of the greatest and most influential punk rock bands of all time. Critic Rick Anderson praises Miller's "ability to meld the raw directness of hardcore punk with an almost supernatural virtuosity without sacrificing the power of either approach".