ENSI Poitiers (École Nationale Supérieure d’Ingénieurs de Poitiers), also known as ENSIP, is an engineering grande école in Poitiers, France. Established in 1984, it is affiliated with the University of Poitiers and focuses on training engineers in environmental protection. It offers diplomas in energy and environment (EE) and in water and civil engineering (GEGC).

Its roots come from Institut de sciences et techniques de Poitiers, a department of the University of Poitiers created in 1972. The Graduate Engineering School took over from it and was established in 1984. Then its buildings have been moved in 1996, in the campus, and it is located with the number B1.

At the beginning, the French grande école was called École supérieure d'ingénieurs de Poitiers (ESIP). In 2010 it changed its name.

The presidents of ENSIP were chronologically Michel Blanchard, Marcel Doré, Jean-Hugues Thomassin, Bernard Legube and Jean-Yves Chenebault.

The admission is decided after concourse at the end of preparatory classes, a highly selective system. It is also possible to be admitted after a Diplôme universitaire de technologie for the best of their promotions.

Students can receive two diplomas: Energy and Water and civil engineering which lead to :

In partnership with Centrale Lille and ISAE-ENSMA, ENSIP is a part of the prestigious International Master's Program in Turbulence. At the end of this highly selective two-year program, students are awarded a master's degree in Fluid Dynamics and Turbulence.

ENSIP students can also develop a double-competence with IAE Poitiers and their master's in business administration.