The present invention provides a negative tone photosensitive composition for EUV light, capable of forming a pattern, in which occurrence of missing defects is suppressed and pattern collapse is suppressed. The present invention also provides a pattern forming method and a method for manufacturing an electronic device. The negative tone photosensitive composition for EUV light of an embodiment of the present invention includes a resin A having a repeating unit having an acid-decomposable group with a polar group being protected with a protective group that is eliminated by the action of an acid, and a photoacid generator, in which a ClogP value of the resin after elimination of the protective group from the resin A is 1.4 or less, a value x calculated by Expression (1) is 1.2 or more, and the value x calculated by Expression (1) and a value y calculated by Expression (2) satisfy a relationship of Expression (3).