O 2 was an O 2 class patrol submarines of the Royal Netherlands Navy.

The submarine was ordered on 1 June 1909 and 11 October that year the O 2 was laid down in Flushing at the shipyard of De Schelde.

In the autumn of that year, trials were held and a depth of 40 meters was reached with no crew on board.

In the autumn of 1913 the O 2 held a torpedo exercise with the HNLMS Jacob van Heemskerck.

Submarine personnel escaped the ship through the tower hatch.