Black September was the conflict fought in Jordan between the JAF and the PLO primarily in September 1970.

Black September may also refer to:

• Black September Organization, a Palestinian militant organization
• Black September (comics), a reboot of Malibu Comics' Ultraverse
• Suai Church massacre, also referred to as the Black September massacre (Portuguese: Massacre Setembro Negro), a 1999 massacre in Timor-Leste