Předboj is a municipality and village in Prague-East District in the Central Bohemian Region of the Czech Republic.

The brook Kojetický potok flows through the municipality and supplies a system of several fishponds there.

The first written mention of Předboj is from 1253, when King Wenceslaus I donated the village to the Knights of the Cross with the Red Star.

In 1671, when Předboj was owned by the St. George's Convent in Prague, the village was annexed to the Panenské Břežany estate.

The only protected cultural monument in the municipality are terrain remains of a medieval fortress that stood here in the 13th–15th century, now an archaelogical site.