SnOx thin films that were rf-sputter-deposited under various gas flow ratios ([O2]/([O2] + [Ar]) OFR = 3.0, 3.6, 4.2 and 4.8 %) were rapidly annealed using atmospheric pressure plasma jets (APPJs) in temperature range of ~350–386 °C for up to 5 min. The original electron probe micro-analysis [O] contents in the as-deposited films were ~25, ~30, ~35 and ~40 % for films deposited at ([O2]/([O2] + [Ar]) gas flow ratios OFR = 3.0, 3.6, 4.2 and 4.8 %, respectively. APPJ annealing increased the [O] content to ~35 % for films deposited at OFR = 3.0 and 3.6 %, where the [O] content remained in similar levels for films deposited at OFR = 4.2 and 4.8 %. Crystalline metallic Sn was identified in films as-deposited at OFR = 3.0 and 3.6 %; on the other hand, an X-ray amorphous SnOx phase was identified in films as-deposited at OFR = 4.2 and 4.8 %. Crystallization and oxidation by APPJ annealing improved the transmittance and blue-shifted the absorption band edge to ~420 nm. All APPJ-annealed films exhibit n-type conductivity that may be contributed by the mixed phases of SnO, SnO2 and a small amount of Sn.