A line of flight or a line of escape (French: ligne de fuite) is a concept developed by Gilles Deleuze and Félix Guattari in their work Capitalism and Schizophrenia. It describes one out of three lines forming what Deleuze and Guattari call assemblages, and serves as a factor in an assemblage that ultimately allows it to change and adapt to said changes, which can be associated with new sociological, political and psychological factors. Translator Brian Massumi notes that in French, "Fuite covers not only the act of fleeing or eluding but also flowing, leaking, and disappearing into the distance (the vanishing point in a painting is a point de fuite). It has no relation to flying."

In the first chapter of the second volume of their Capitalism and Schizophrenia project, A Thousand Plateaus (1980), the concept is used to define a "rhizome":

Multiplicities are defined by the outside: by the abstract line, the line of flight or deterritorialization according to which they change in nature and connect with other multiplicities. The plane of consistency (grid) is the outside of all multiplicities. The line of flight marks: the reality of a finite number of dimensions that the multiplicity effectively fills; the impossibility of a supplementary dimension, unless the multiplicity is transformed by the line of flight; the possibility and necessity of flattening all of the multiplicities on a single plane of consistency or exteriority, regardless of their number of dimensions.