Zambales's 1st congressional district

Zambales's 1st congressional district is one of the two congressional districts of the Philippines in the province of Zambales. It has been represented in the House of Representatives since 1987. The district consists of the city of Olongapo and adjacent municipalities in the southernmost part of Zambales, namely Castillejos, San Marcelino and Subic. It is currently represented in the 19th Congress by Jefferson F. Khongun of the Nacionalista Party (NP).

Representation history
{| class=wikitable ! rowspan="2" | # ! rowspan="2" colspan=2 | Member ! colspan=2 | Term of office ! rowspan="2" | Congress ! rowspan="2" | Party ! rowspan="2" | Electoral history ! rowspan="2" | Constituent LGUs !Start!!End
 * colspan="9" style="text-align:center;" |
 * colspan="9" style="text-align:center;" |

Zambales's 1st district for the House of Representatives of the Philippines

 * colspan="9" style="text-align:center;" | District created February 2, 1987 from Zambales's at-large district.
 * rowspan="2" style="text-align:center;" | 1
 * rowspan="2" style="color:inherit;background:;" |
 * rowspan="2" | Katherine H. Gordon
 * rowspan="2" | June 30, 1987
 * rowspan="2" | June 30, 1995
 * style="text-align:center;" | 8th
 * rowspan="2" | Nacionalista
 * Elected in 1987.
 * rowspan="12" style="text-align:center;" | 1987–present Castillejos, Olongapo, San Marcelino, Subic
 * style="text-align:center;" | 9th
 * Re-elected in 1992.
 * rowspan="3" style="text-align:center;" | 2
 * rowspan="3" style="color:inherit;background:;" |
 * rowspan="3" | James J. Gordon Jr.
 * rowspan="3" | June 30, 1995
 * rowspan="3" | June 30, 2004
 * style="text-align:center;" | 10th
 * rowspan="3" | Lakas
 * Elected in 1995.
 * style="text-align:center;" | 11th
 * Re-elected in 1998.
 * style="text-align:center;" | 12th
 * Re-elected in 2001.
 * rowspan="3" style="text-align:center;" | 3
 * rowspan="2" style="color:inherit;background:;" |
 * rowspan="3" | Mitos Magsaysay
 * rowspan="3" | June 30, 2004
 * rowspan="3" | June 30, 2013
 * style="text-align:center;" | 13th
 * rowspan="2" | Lakas
 * Elected in 2004.
 * style="text-align:center;" | 14th
 * Re-elected in 2007.
 * style="color:inherit;background:;" |
 * style="text-align:center;" | 15th
 * UNA
 * Re-elected in 2010.
 * rowspan="3" style="text-align:center;" | 4
 * style="color:inherit;background:;" |
 * rowspan="3" | Jeffrey D. Khonghun
 * rowspan="3" | June 30, 2013
 * rowspan="3" | June 30, 2022
 * style="text-align:center;" | 16th
 * NPC
 * Elected in 2013.
 * style="color:inherit;background:;" |
 * style="text-align:center;" | 17th
 * Liberal
 * Re-elected in 2016.
 * style="color:inherit;background:;" |
 * style="text-align:center;" | 18th
 * Nacionalista
 * Re-elected in 2019.
 * style="text-align:center;" | 5
 * style="color:inherit;background:;" |
 * Jefferson F. Khongun
 * June 30, 2022
 * Incumbent
 * style="text-align:center;" | 19th
 * Nacionalista
 * Elected in 2022.
 * }
 * style="text-align:center;" | 18th
 * Nacionalista
 * Re-elected in 2019.
 * style="text-align:center;" | 5
 * style="color:inherit;background:;" |
 * Jefferson F. Khongun
 * June 30, 2022
 * Incumbent
 * style="text-align:center;" | 19th
 * Nacionalista
 * Elected in 2022.
 * }
 * }