| Alejandro Reyes | |
| Order: | President of the Supreme Court |
| Term: | 1882 |
| Predecessor: | José Miguel Barriga Castro |
| Successor: | Álvaro Covarrubias Ortúzar |
| Order1: | Justice of the Supreme Court of Chile |
| Term Start1: | 1870 |
| Term End1: | 1883 |
| Order2: | Senator |
| Term Start2: | 1870 |
| Term End2: | 1882 |
| Predecessor2: | José Alejo Valenzuela Díaz |
| Successor2: | Elías Fernández Albano |
| Order3: | Minister of Foreign Affairs |
| Term Start3: | 1868 |
| Term End3: | 1870 |
| Predecessor3: | Miguel Luis Amunátegui |
| Successor3: | Belisario Prats |
| Order4: | Minister of the Interior |
| Term Start4: | 1868 |
| Term End4: | 1870 |
| Predecessor4: | Miguel Luis Amunátegui |
| Successor4: | Belisario Prats |
| Order5: | Minister of Finance |
| Term Start5: | 1864 |
| Term End5: | 1869 |
| Predecessor5: | Domingo Santa María |
| Successor5: | Melchor Concha y Toro |
| Order6: | Deputy |
| Term Start6: | 1864 |
| Term End6: | 1867 |
| Constituency6: | Itata |
| Predecessor6: | Andrés Chacón Barry |
| Successor6: | Nicolás Figueroa Brito |
| Term Start7: | 1858 |
| Term End7: | 1861 |
| Constituency7: | Melipilla and La Victoria |
| Predecessor7: | Miguel Barros Morán |
| Successor7: | Manuel Briceño Ibáñez |
| Term Start8: | 1855 |
| Term End8: | 1858 |
| Constituency8: | San Fernando |
| Predecessor8: | José Bisquert de la Barrera |
| Successor8: | Ignacio Errázuriz Salas |
| Term Start9: | 1852 |
| Term End9: | 1855 |
| Predecessor9: | Juan Bello Dunn |
| Successor9: | Nicanor Letelier Cruz |
| Constituency9: | Los Angeles and Yungay |
| Birth Name: | Alejandro Matías Luis Ignacio Reyes Cotapos |
| Birth Date: | February 24, 1825 |
| Birth Place: | Santiago, Chile |
| Death Place: | Santiago, Chile |
| Spouse: | Hortensia Lavalle Correas Fanny Ovalle Vicuña |
| Party: | National |
Alejandro Matías Luis Ignacio Reyes Cotapos (24 February 1825 – 8 January 1884) was a Chilean lawyer and politician.
Reyes was born in Santiago to Ignacio de Reyes Saravia and Micaela Pérez Cotapos de la Lastra. He married twice, first to Hortensia Lavalle Correas, then Fanny Ovalle Vicuña. Reyes earned a degree in law from the University of Chile in 1845.
Throughout his political career, Reyes remained allied with Manuel Montt and Antonio Varas, whose supporters formally established the National Party in 1857. In 1849, Reyes was named an alternate member of the Chamber of Deputies from Caupolicán, but never took office. He began working for the Santiago municipal government in 1851. Reyes won his first parliamentary election the next year, taking a seat in the Chamber of Deputies as a representative of Los Ángeles and Yungay. He was reelected in 1855 from San Fernando and again in 1858, from Melipilla and La Victoria, a district of Santiago. As a legislator, Reyes served on the industry, treasury, and war committees.
Upon his return from exile in Europe in 1862, Reyes became a diplomat and helped reach treaties with Ecuador and Costa Rica. Later, Reyes aided in the drafting of the legal codes regulating commerce, civil actions, and criminal activity. He was Minister of Finance between 1864 and 1869. From 1868 to 1870, Reyes served as concurrently as interior and foreign minister. Reyes also returned to the Chamber of Deputies, representing Itata between 1863 and 1867. After his term ended, Reyes became a judge on the Santiago Appeals Court. He was appointed to the Supreme Court of Chile in 1870, and concurrently took office as a senator from Curicó. Reyes stepped down from the Senate in 1882, and relinquished his judgeship in 1883, before dying in Santiago on 8 January 1884. Outside of politics, Reyes nurtured an interest in winemaking, and started a vineyard in Buin.