Floud is a surname, and may refer to:

• Francis Floud (1875–1965), High Commissioner to Canada
• Peter Floud (1911–1960), civil servant
• Jean Floud (née Jean MacDonald) (1915–2013), sociologist and wife of Peter Floud.
• Bernard Floud (1915–1967), television executive and MP
• Roderick Floud (1942–), economic historian

• Orthogneiss
• Orthogoal collocation
• Orthogonal array
• Orthogonal Arrays
• Orthogonal circular ensemble
• Orthogonal collocation
• Orthogonal convexity
• Orthogonal coordinate system
• Orthogonal diagonalization
• Orthogonal ensemble
• Orthogonal Frequency Division Multiplexing
• Orthogonality principle
• Orthogonality principle and error minimization
• Orthogonality programming
• Orthogonality (programming)
• Orthogonal Polarization Spectral imaging
• Orthogonal polarization spectral imaging
• Orthogonal regression
• Orthogonal signal correction
• Orthogonal symmetric Lie algebra
• Orthogonal trajectories
• Orthogonal transform
• Orthogonant
• Orthogonia
• Orthogonia grisea