Number nine may refer to:
- 9 (number), natural number
- Number Nine (album) by Chris Hülsbeck
- Number 9 Audio Group, a recording studio located in Toronto, Ontario, Canada
- Number Nine Visual Technology, a computer hardware manufacturer whose primary business was video cards
- Number nine, repeated phrase on the Beatles recorded composition Revolution 9, famously said to contain a backmasked message
- Number Nine, assistant to Jenny Jump in the Oz books by John R. Neill
Famous quotes containing the word number:
“The quality of moral behaviour varies in inverse ratio to the number of human beings involved.”
—Aldous Huxley (1894–1963)