According to picture below:
Polar molecules are water (H₂O) and ozone (O₃).
Nonpolar molecules are carbon(IV) oxide (CO₂) and oxygen (O₂).
Carbon(IV) oxide is nonpolar because CO₂ is linear molecule and the oxygen atoms are symmetrical (bond angles 180°).
Water is polar because of the bent shape of the molecule.
Ozone is polar because of the bent shape like water.
Oxygen is nonpolar because double linear bond.