Castellón () is one of the 52 constituencies represented in the Congress of Deputies, the lower chamber of the Spanish parliament, the . The constituency (whose boundaries correspond to those of the homonymous province) currently elects five deputies. The electoral system uses the D'Hondt method and closed-list proportional voting, with a minimum threshold of three percent.

Electoral system The constituency was created as per the Political Reform Law and was first contested in the 1977 general election. The Law provided for the provinces of Spain to be established as multi-member districts in the Congress of Deputies,. with this regulation being maintained under the Spanish Constitution of 1978.. Additionally, the Constitution requires for any modification of the provincial limits to be approved under an organic law, needing an absolute majority in the Cortes Generales..

Voting is based on universal suffrage, comprising all Spanish nationals over 18 years of age with full political rights, provided that they have not been deprived of the right to vote by a final sentence.. The only exception was in 1977, when this was limited to nationals over 21 years of age and in full enjoyment of their political and civil rights.; . Amendments in 2011 required non-resident citizens to apply for voting, a system known as "begged" voting ().. which was abolished in 2022. Further, amendments in 2018 granted the right to vote to those legally incapacitated. The Congress of Deputies has a minimum of 300 and a maximum of 400 seats, with electoral provisions fixing its size at 350. Of these, 348 are elected in 50 multi-member constituencies corresponding to the provinces of Spain—each of which is assigned an initial minimum of two seats and the remaining 248 distributed in proportion to population—using the D'Hondt method and closed-list proportional voting, with a three percent-threshold of valid votes (including blank ballots) in each constituency. The remaining two seats are allocated to Ceuta and Melilla as single-member districts elected by plurality voting.; ; ; . The use of this electoral method may result in a higher effective threshold depending on district magnitude and vote distribution. The law does not provide for by-elections to fill vacant seats; instead, any vacancies arising after the proclamation of candidates and during the legislative term are filled by the next candidates on the party lists or, when required, by designated substitutes.; .

The electoral law allows for parties and federations registered in the interior ministry, alliances and groupings of electors to present lists of candidates. Parties and federations intending to form an alliance are required to inform the relevant electoral commission within 10 days of the election call—15 before 1985—whereas groupings of electors need to secure the signature of at least one percent of the electorate in the constituencies for which they seek election—one permille of the electorate, with a compulsory minimum of 500 signatures, until 1985—disallowing electors from signing for more than one list. Also since 2011, parties, federations or alliances that have not obtained a mandate in either chamber of the at the preceding election are required to secure the signature of at least 0.1 percent of electors in the aforementioned constituencies.; . Amendments in 2007 required a balanced composition of men and women in the electoral lists, so that candidates of either sex made up at least 40 percent of the total composition; further amendments in 2024 required the use of a zipper system..

Deputies Deputies 1977–present Legislature Election Distribution Constituent 1977 2 1 2 1st 1979 2 3 2nd 1982 3 2 3rd 1986 3 2 4th 1989 3 2 5th 1993 2 3 6th 1996 2 3 7th 2000 2 3 8th 2004 2 3 9th 2008 2 3 10th 2011 2 3 11th 2015 1 1 1 2 12th 2016 1 1 1 2 13th 2019 (Apr) 1 2 1 1 14th 2019 (Nov) 1 2 1 1 15th 2023 2 2 1

General elections 2023 + Summary of the 23 July 2023 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− People's Party (PP) 108,302 35.17 +11.34 2 +1 Spanish Socialist Workers' Party (PSOE) 100,530 32.65 +4.10 2 ±0 Vox (Vox) 48,913 15.88 –2.75 1 ±0 Commitment–Unite: We Unite to Win (Sumar–Compromís)1 44,187 14.35 –5.14 0 –1 Animalist Party with the Environment (PACMA)2 1,968 0.64 –0.20 0 ±0 Workers' Front (FO) 721 0.23 New 0 ±0 Zero Cuts (Recortes Cero) 493 0.16 +0.07 0 ±0 Spanish Phalanx of the CNSO (FE de las JONS) 161 0.05 ±0.00 0 ±0 Blank ballots 2,655 0.86 +0.10 Total 307,930 5 ±0 Valid votes 307,930 98.83 –0.15 Invalid votes 3,651 1.17 +0.15 Votes cast / turnout 311,581 72.32 +1.61 Abstentions 119,249 27.68 –1.61 Registered voters 430,830 Sources

November 2019 + Summary of the 10 November 2019 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− Spanish Socialist Workers' Party (PSOE) 84,078 28.55 –0.93 2 ±0 People's Party (PP) 70,176 23.83 +3.49 1 ±0 Vox (Vox) 54,849 18.63 +6.65 1 +1 United We Can (Podemos–EUPV) 39,251 13.33 –0.60 1 ±0 Citizens–Party of the Citizenry (Cs) 20,302 6.89 –9.39 0 –1 More Commitment (Més Compromís)1 18,140 6.16 +0.83 0 ±0 Animalist Party Against Mistreatment of Animals (PACMA) 2,483 0.84 –0.24 0 ±0 Republican Left of the Valencian Country (ERPV) 1,106 0.38 +0.11 0 ±0 Forward–The Greens (Avant/Adelante–LV) 405 0.14 –0.05 0 ±0 Spanish Communist Workers' Party (PCOE) 379 0.13 New 0 ±0 For a Fairer World (PUM+J) 370 0.13 +0.03 0 ±0 Zero Cuts–Green Group (Recortes Cero–GV) 257 0.09 –0.02 0 ±0 Communist Party of the Peoples of Spain (PCPE) 194 0.07 –0.03 0 ±0 Spanish Phalanx of the CNSO (FE de las JONS) 137 0.05 –0.02 0 ±0 At Once Valencian Community (aUna CV) 104 0.04 New 0 ±0 Blank ballots 2,238 0.76 +0.03 Total 294,469 5 ±0 Valid votes 294,469 98.98 +0.21 Invalid votes 3,023 1.02 –0.21 Votes cast / turnout 297,492 70.71 –4.89 Abstentions 123,249 29.29 +4.89 Registered voters 420,741 Sources

April 2019 + Summary of the 28 April 2019 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− Spanish Socialist Workers' Party (PSOE) 92,379 29.48 +7.40 2 +1 People's Party (PP) 63,756 20.34 –15.34 1 –1 Citizens–Party of the Citizenry (Cs) 51,017 16.28 +1.53 1 ±0 United We Can (Podemos–EUPV)1 43,656 13.93 –10.23 1 ±0 Vox (Vox) 37,551 11.98 +11.74 0 ±0 Commitment: Bloc–Initiative–Greens Equo (Compromís 2019) 16,713 5.33 New 0 ±0 Animalist Party Against Mistreatment of Animals (PACMA) 3,381 1.08 +0.08 0 ±0 Republican Left of the Valencian Country (ERPV) 859 0.27 New 0 ±0 Forward–The Greens (Avant/Adelante–LV) 586 0.19 New 0 ±0 Zero Cuts–Green Group (Recortes Cero–GV) 341 0.11 –0.08 0 ±0 Communist Party of the Peoples of Spain (PCPE) 329 0.10 –0.03 0 ±0 For a Fairer World (PUM+J) 302 0.10 New 0 ±0 Spanish Phalanx of the CNSO (FE de las JONS) 222 0.07 –0.09 0 ±0 Blank ballots 2,301 0.73 +0.04 Total 313,393 5 ±0 Valid votes 313,393 98.77 –0.20 Invalid votes 3,909 1.23 +0.20 Votes cast / turnout 317,302 75.60 +3.01 Abstentions 102,412 24.40 –3.01 Registered voters 419,714 Sources

2016 + Summary of the 26 June 2016 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− People's Party (PP) 106,746 35.68 +3.86 2 ±0 The Valencian Way (Podemos–Compromís–EUPV)1 72,281 24.16 –3.09 1 ±0 Spanish Socialist Workers' Party (PSOE) 66,062 22.08 +0.56 1 ±0 Citizens–Party of the Citizenry (C's) 44,121 14.75 –0.87 1 ±0 Animalist Party Against Mistreatment of Animals (PACMA) 2,985 1.00 +0.27 0 ±0 Citizens of Democratic Centre (CCD) 1,712 0.57 –0.12 0 ±0 Vox (Vox) 711 0.24 –0.06 0 ±0 Union, Progress and Democracy (UPyD) 662 0.22 –0.34 0 ±0 Zero Cuts–Green Group (Recortes Cero–GV) 561 0.19 +0.03 0 ±0 Spanish Phalanx of the CNSO (FE de las JONS) 476 0.16 New 0 ±0 We Are Valencian (SOMVAL) 415 0.14 –0.01 0 ±0 Communist Party of the Peoples of Spain (PCPE) 403 0.13 –0.03 0 ±0 Blank ballots 2,069 0.69 +0.01 Total 299,204 5 ±0 Valid votes 299,204 98.97 +0.03 Invalid votes 3,120 1.03 –0.03 Votes cast / turnout 302,324 72.59 –2.39 Abstentions 114,167 27.41 +2.39 Registered voters 416,491 Sources

2015 + Summary of the 20 December 2015 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− People's Party (PP) 98,474 31.82 –21.02 2 –1 It is Time (Podemos–Compromís)1 74,732 24.15 +20.14 1 +1 Spanish Socialist Workers' Party (PSOE) 66,590 21.52 –8.04 1 –1 Citizens–Party of the Citizenry (C's) 48,328 15.62 New 1 +1 United Left of the Valencian Country–Popular Unity in Common (EUPV–UPeC) 9,605 3.10 –2.19 0 ±0 Animalist Party Against Mistreatment of Animals (PACMA) 2,252 0.73 +0.32 0 ±0 Citizens of Democratic Centre (CCD) 2,137 0.69 New 0 ±0 Union, Progress and Democracy (UPyD) 1,743 0.56 –3.49 0 ±0 Vox (Vox) 921 0.30 New 0 ±0 Communist Party of the Peoples of Spain (PCPE) 509 0.16 –0.03 0 ±0 Zero Cuts–Green Group (Recortes Cero–GV) 489 0.16 New 0 ±0 National Democracy (DN) 471 0.15 New 0 ±0 We Are Valencian (SOMVAL) 467 0.15 New 0 ±0 Valencian Country Now (Ara PV)2 413 0.13 –0.38 0 ±0 Feminist Initiative (IFem) 261 0.08 New 0 ±0 Blank ballots 2,093 0.68 –0.72 Total 309,485 5 ±0 Valid votes 309,485 98.94 +0.61 Invalid votes 3,330 1.06 –0.61 Votes cast / turnout 312,815 74.98 +2.24 Abstentions 104,382 25.02 –2.24 Registered voters 417,197 Sources

2011 + Summary of the 20 November 2011 Congress of Deputies election results in Castellón Parties and alliances Popular vote Seats Votes % ±pp Total +/− People's Party (PP) 156,683 52.84 +3.86 3 ±0 Spanish Socialist Workers' Party (PSOE) 87,657 29.56 –14.62 2 ±0 United Left of the Valencian Country–The Greens: Plural Left (EUPV–EV) 15,692 5.29 +3.20 0 ±0 Union, Progress and Democracy (UPyD) 12,008 4.05 +3.49 0 ±0 Bloc–Initiative–Greens–Equo: Commitment Coalition (Compromís–Q)1 11,890 4.01 +3.00 0 ±0 Spain 2000 (E–2000) 3,687 1.24 +0.91 0 ±0 Republican Left of the Valencian Country (ERPV) 1,501 0.51 +0.17 0 ±0 Animalist Party Against Mistreatment of Animals (PACMA) 1,223 0.41 +0.24 0 ±0 Pirate Party (Pirata) 1,001 0.34 New 0 ±0 Communist Party of the Peoples of Spain (PCPE) 563 0.19 +0.13 0 ±0 Internationalist Socialist Workers' Party (POSI) 284 0.10 +0.07 0 ±0 Communist Unification of Spain (UCE) 180 0.06 New 0 ±0 Blank ballots 4,146 1.40 +0.32 Total 296,515 5 ±0 Valid votes 296,515 98.33 –0.93 Invalid votes 5,033 1.67 +0.93 Votes cast / turnout 301,548 72.74 –5.09 Abstentions 113,013 27.26 +5.09 Registered voters 414,561 Sources

2008