Fourier (pronounced , French pronunciation /fu.ʁi'e/) can mean:

• Jean Baptiste Joseph Fourier, a French mathematician and physicist.
• Charles Fourier, a French utopian socialist thinker.
• The Fourier series which can reduce any periodic function to a sum of sine and cosine terms.
• The Fourier transform, an integral transform that re-expresses a function in terms of sinusoidal basis functions.