| Calexico–Mexicali | |
| Settlement Type: | Transborder agglomeration of the Californias |
| Subdivision Type: | Country |
| Subdivision Name: |  United States Mexico |
| Subdivision Type1: | State |
| Subdivision Name1: | California Baja California |
| Subdivision Type3: | Principal cities |
| Subdivision Name3: | Mexicali - Calexico - El Centro - Imperial - Santa Isabel |
| Population As Of: | 2010 est. |
| Population Footnotes: | [1] |
| Population Note: | MSA/CSA = 2010, Urban = 2000 |
| Population Blank2 Title: | MSA |
| Population Blank2: | 1,000,000 (19th) |
| Timezone: | PST |
| Utc Offset: | -8 |
| Timezone Dst: | PDT |
| Utc Offset Dst: | -7 |
Calexico–Mexicali is a transborder agglomeration in southeastern California (in the United States) and northwestern Baja California (in Mexico) with its center being the border between the sister cities of Calexico and Mexicali. The agglomeration lies within a large geologic region known as the Salton Trough with the city of Calexico located in the Imperial Valley on the United States side of the border, and Mexicali located in the Mexicali Valley on the Mexico side of the border.
Calexico–Mexicali is one of two transborder agglomerations on the California-Baja California Border; the other is San Diego–Tijuana.