Jaša Tomić (Serbian Cyrillic: Јаша Томић) is a town located in the municipality of Sečanj, in the Central Banat District of Serbia.

It is assumed that the old village name, Modoš, derived from the Latin phrase modus transciendi, which in English means way of crossing the river.

Findings from the Neolithic, Bronze and Iron Ages have been found, including a burial from the Bosut-Basarabi culture of the 9th century BC.

Two other medieval settlements existed nearby: Új Rév (Uj Rev, Oređ) and Oroszi (Orosi).

[1] In 1660–6, Katastig of the Patriarchal Monastery of Peć recorded the names of Serb inhabitants of Modoš - priest Jaftimije and priest Zaharije, Ilija, Granny Romana, Milić Radojević, Vladislav, Rusmir, Vuja, Komlenija, Avram, Gavril Panov, Mata, Radomir, Cveja Vranešev, Andreja, and Petar.

In the second half of the 18th century, some Serbs from Pomorišje and Sečanj settled in Modoš, as did some Hungarians, Germans, Slovaks and Bulgarians.

Some local Serbs who were dissatisfied with this administrative change left Modoš and settled in the Banatian Military Frontier.

In 1848–9, Modoš was part of the autonomous Serbian Vojvodina and in 1849-60 of the Voivodeship of Serbia and Temes Banat, a separate Habsburg crown land.

By 1910, the population of the town was ethnically mixed, the largest group being the Germans, alongside sizeable Hungarian and Serb communities.

The German population had mostly fled from Jaša Tomić by the end of the war (in 1944), while some mainly Serb colonists from Bosnia and Herzegovina, Central Serbia and Croatia settled in the town from 1945.