What are the most important qualities to becoming a successful Army Officer?

The ability to learn and be humble. All of these NCOs on here are dead on. I had a Platoon Sergeant tell me when I was a young 2LT "Sir, you are down here for a year, maybe two (at platoon level), some of us are down here our whole careers." Ever seen a platoon function without a PL? I have, quite well. The NCO hated all the meetings, but they got it done. Knowledge is critical, but practical application is where it is at. You gotta be able to tell the difference between someone you need to seek advice from and not to seek advice from. Learn from your mistakes and those around you. Stay out of the RED.

The wisdom to listen to the NCOs who learned things the hard way, the ability to balance the politics of officer life with the welfare of your troops, and a supply officer that knows where the excess property is stashed come inventory time.

Cadet PVT (Join to see) Great question! As an NCO, I appreciated officers that would listen and learn from their NCO's and Staff NCO's. Good officers will look out for the welfare of their men. A rule that applies to everyone is to learn from your mistakes. You will make mistakes, just don't make the same mistake twice.