Anti-Mexican sentiment is a fear, distrust, stereotype, hostility and aversion of people of Mexican descent, Mexican culture and/or Spanish as well other languages of Mexico. It is mostly associated with Mexican Americans in the United States.

In general it is closely associated with Mexican and American Independence wars, and the struggle over Southwestern territories that once belonged to Spain through the establishment of building Catholic Missions. This eventually would lead to war between the two nations and the defeat of Mexico which came with a great lost of territory. In the 20th century, anti-Mexican sentiment continued to grow after the Zimmerman Telegram incident between the Mexican government during the Mexican Revolution and the German Empire during World War I, and again the secret talks with the party of Germany in the 1930's and early 1940's to invade the Southwest. And most of all, anti-Mexican sentiment in the USA stemmed from illegal immigration. Anti-American, militaristic and purported separatist Mexican nationalist groups in the United States such as M.E.Ch.A and La Raza which have been characterized as calling for annexation of the Southwest United States into a Mexican republic called Aztlán have contributed to the backlash against Mexican immigration. Neither M.E.Ch.A nor La Raza have separatist agendas.

Mexican Americans are Americans of Mexican descent. As of July 2009, Mexican Americans make up 10.3% of the United States' population with over 31,689,000 Americans listed as of Mexican ancestry. Mexican Americans comprise 66% of all Hispanics and Latinos in the United States. The United States is home to the second largest Mexican community in the world second only to Mexico itself comprising nearly 22% of the entire Mexican origin population of the world. Canada is a distant third with a Mexican origin population of 37,000 as of 2001 although increasing to 61,505 as of 2006. In addition, as of 2008 there were approximately 7,000,000 undocumented Mexicans living in the United States which if included in the count would increase the US share to over 28% of the world's Mexican origin population (Note that some of the undocumented would be captured in the US Census count depending on their willingness to provide information). Over 60% of all Mexican Americans reside in the states of California and Texas. Most Mexican Americans are the descendants of the Indigenous peoples of Mexico and/or Europeans, especially Spaniards.