Blay is a surname. Notable people with the surname include:
Andre Blay, American businessman, film producer and studio executiveEddie Blay (1937–2006), Ghanaian boxerEva Alterman Blay (born 1937), Brazilian sociologist and politicianFreddie Blay (born 1942), Ghanaian lawyer and politicianGeorge Blay (born 1980), Ghanaian footballerJ. Benibengor Blay (born 1915), Ghanaian journalist, writer, publisher and politicianPep Blay (born 1966), Catalan writer, script writer and music journalistRuth Blay (died 1768), last woman executed in New Hampshire