[1] Voting for the Parliament was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered in Cantabria and in full enjoyment of their political rights.

[2] The expat vote system was attributed responsibility for a major decrease in the turnout of Spaniards abroad during the years it had been in force.

[3] The 35 members of the Parliament of Cantabria were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of five percent of valid votes—which included blank ballots—being applied regionally.

[1][4][5] The president had the prerogative to dissolve the Parliament of Cantabria and call a snap election, provided that no motion of no confidence was in process, no nationwide election was due and some time requirements were met: namely, that dissolution did not occur either during the first legislative session or within the legislature's last year ahead of its scheduled expiry, nor before one year had elapsed since a previous dissolution.

[4][5] Below is a list of the main parties and electoral alliances which contested the election: On 19 December 2019, Félix Álvarez resigned as leader of Citizens (CS) in Cantabria, citing "disagreements" with the party's leadership after a scandal broke out over the one-day hiring of Cs former leading candidate for the Congress of Deputies in the region, Rubén Gómez, a contract which Álvarez had publicly denied from having taken place.

The highest percentage figure in each polling survey is displayed with its background shaded in the leading party's colour.