Castelfranco di Sotto

{{Infobox Italian comune

| name = Castelfranco di Sotto

| official_name = Comune di Castelfranco di Sotto

| native_name =

| image_skyline = Castelfranco di Sotto, Torre mediavale.jpg

| imagesize =

| image_alt =

| image_caption = The bell tower seen from Corso Bertoncini

| image_shield = Castelfranco di Sotto-Stemma.png

| shield_alt =

| image_map =

| map_alt =

| map_caption =

| pushpin_label_position =

| pushpin_map_alt =

| coordinates = {{coord|43|42|N|10|45|E|type:city(11,789)_region:IT|display=inline}}

| coordinates_footnotes =

| region = Tuscany

| province = Pisa (PI)

| frazioni = Orentano, Villa Campanile, Galleno (partly), Staffoli (partly)

| mayor_party =

| mayor = Fabio Mini

| area_footnotes =

| area_total_km2 = 48.4

| population_footnotes =

| population_total = 12179

| population_as_of = 31 October 2008All demographics and other statistics: Italian statistical institute Istat.

| pop_density_footnotes =

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| elevation_footnotes =

| elevation_m = 16

| twin1 =

| twin1_country =

| saint = San Severo

| day = November 18

| postal_code = 56022

| area_code = 0571

| website = {{official website|http://www.comune.castelfranco-di-sotto.pi.it/}}

| footnotes =

}}

Castelfranco di Sotto is a comune (municipality) in the Province of Pisa in the Italian region Tuscany, located about {{convert|40|km|mi}} west of Florence and about {{convert|30|km|mi}} east of Pisa.

Castelfranco di Sotto borders the following municipalities: Altopascio, Bientina, Fucecchio, Montopoli in Val d'Arno, San Miniato, Santa Croce sull'Arno, Santa Maria a Monte.