Lombardy 4 is one of the 29 constituencies (Italian: circoscrizioni) represented in the Chamber of Deputies, the lower house of the Italian parliament.

[2] The constituency currently elects 17 deputies.

Its boundaries correspond to those of the provinces of Cremona, Lodi, Mantua and Pavia, within the Lombardy region.

The electoral system uses a parallel voting system, which act as a mixed system, with 37% of seats allocated using a first-past-the-post electoral system and 61% using a proportional method, with one round of voting.

[3] The constituency was established by the Rosato law on 3 November 2017.