The Keisei 3100 series (京成3100形) is an electric multiple unit (EMU) train type operated by the private railway operator Keisei Electric Railway on Narita Sky Access Line services.

[3] As of 13 November 2021,[update] the fleet consists of six[4] 8-car sets which are formed as follows.

[5] The interior includes passenger information displays, security cameras,[6] and wheelchair spaces.

[5] In addition, the seat backs are approximately 170 millimetres (6.7 in) higher than those of the 3000 series.

[10][11] In early 2023, Keisei announced that an additional set would be purchased as part of its 2023 capital investment plan.