Barangay San Isidro is also part of the West district division of 76 Barangays in Tarlac City. Barangay Dolores bound it on the Northwest, Barangay Aguso on the Northeast, Sapang Maragul on the West, and Cut-Cut 1st on the Southeast.

Barangay San Isidro classified as Urban Barangay, it has a total population of nine thousand six hundred fifty two (9,652) as of 2005, and a household population of one thousand six hundred thirty seven (1,637).

Barangay San Isidro is more on commercial and industrial area because different kinds of business firms situated here. They are general merchandize, restaurants, and resorts and so on. The other part of San Isidro dedicated to agriculture. Farming is also one of their major source livelihoods. Some of them were employees, laborers, drivers, construction workers and so on. Other has their own mini business such as sari-sari stores, canteen and others.

Years ago, this place was blessed with a large variety of bamboo grass. There were only 20 numbers of households’ situated in this land, the major source of their livelihood is farming. Because of the spiritual and imaginative values a man who is devotee of Saint San Isidro (the Patron of the farmers) to be able for to produce more crops they decided to name their barangay after their Patron. From the influenced of the different neighboring places approximately 80% of the population of this barangay are Roman Catholic, the other half of the percentage is combination of different religion like Iglesia Ni Cristo, and so on.

The first settlers of this place are the Espinosa, Dimacali, Lumibao, and Ramos family.

Ninety percent of the total populations are Pampango, and the rest are Tagalog, Bisaya, Pangasinense, and Ilocano.

Barangay San Isidro celebrates their feast day every May 15 as a thanksgiving to the patron Saint Isidore the Laborer (San Isidro Labrador). Saint Isidore the Laborer or the Labourer, also known as Isidore the Farmer, or San Isidro Labrador in Spanish, (c. 1070–May 15, 1130), was a Spanish day laborer known for his goodness toward the poor and animals. He is the Catholic patron saint of farmers and Madrid.

Isidore is widely venerated as the patron saint of peasants and day laborers, as he had been one himself. In 1947, at the request of the National Catholic Rural Life Conference, he was officially named patron of farmers, with a feast day on March 22 in all dioceses of the US, with a proper Mass and Office.