| Jan Daniłowicz | |
| House-Type: | Szlachta |
| Noble Family: | Daniłowicz |
| Coa: | Sas |
| Father: | Stanisław Daniłowicz |
| Mother: | Katarzyna Tarło |
| Spouse: | Barbara Krasicka Zofia Żółkiewska |
| Spouse-Type: | Consort |
| Issue: | with Barbara Krasicka Katarzyna Marcjanna with Zofia Żółkiewska Zofia Teofila Daniłowiczówna Stanisław Daniłowicz Jan Daniłowicz Dorota Daniłowiczówna |
| Birth Date: | 1570 |
| Death Date: | 1628 |
| Death Place: | Lwów |
| Full Name: | Jan Daniłowicz na Olesku herbu Sas |
Jan Daniłowicz (1570–1628) was a Polish nobleman, voivode of the Ruthenian Voivodeship and grandfather of King Jan III Sobieski.
He was voivode of the Ruthenian Voivodship since 1613, castellan of Lviv since 1612, Great Krajczy of the Crown since 1600, Great Podczaszy of the Crown, łowczy of Belz, starost of Belz, Busk, Korsuń and Chyhyryn. In his youth he fought with the Tatars. In 1594 he participated in the suppression of the Nalyvaiko Uprising.
With his first wife Barbara Krasicka he had two daughters:
In 1605 he married Zofia Żółkiewska the daughter of Great Hetman of the Crown Stanisław Żółkiewski and had four children: