The name Los Angeles is Spanish for The Angels. There is much more to this name, however.
On Wednesday, August 2, 1769, Father Juan Crespi, a Franciscan priest accompanying the first European land expedition through California, led by Captain Fernando Rivera Y Moncado, described in his journal a "beautiful river from the northwest" located at "34 degrees 10 minutes." They named the river Nuestra Señora de los Angeles de la Porciúncula. In the Franciscan calendar, August 2 was the day of the celebration of the feast of the Perdono at the tiny Assisi chapel of St. Francis of Assisi. Early in St. Francis’ life, the Benedictines had given him this tiny chapel for his use near Assisi. The chapel, ruined and in need of repair, was located on what the Italians called a porziuncola or "very small parcel of land." Painted on the wall behind the altar was a fresco of the Virgin Mary surrounded by angels. Now contained within a Basilica, the chapel was named Saint Mary of the Angels at the Little Portion. The newly discovered "beautiful river" was named in honor of this celebration and this chapel.
In 1781, a new settlement was established along that river. The settlement came to be known as El Pueblo de Nuestra Señora la Reina de los Angeles de Porciúncula or The Town of Our Lady the Queen of Angels of the Little Portion although its official name was simply El Pueblo de la Reina de Los Angeles.
Also see "Pronouncing Los Angeles."