TNF (tumor necrosis factor) is a cell signaling protein (cytokine) involved in systemic inflammation.

TNF may also refer to:

• Talking News Federation, UK charitable organization (see Talking Newspaper Association of the United Kingdom)
• The NetBSD Foundation, US not-for-profit corporation that owns the intellectual property and trademarks associated with the NetBSD operating system
• The North Face, US outdoor products manufacturer
• Third normal form, in database normalization
• Thursday Night Football, NFL weekly sports broadcast
• Tumor necrosis factor superfamily, a protein superfamily
• Tonfanau railway station, Gwynedd, Wales (National Rail station code)
• Toussus-le-Noble Airport