What is the absolute highest rank in the US Army?

Ah Ha, and what is the absolute highest rank in the Navy?

General of the Army (5 stars)

POTUS.

General of the Army--5 star. None since Ike.

The Five Star General was instituted during WW2 to give men like Eisenhower parity with the British Field Marshal. Now We only have the Four Star.

Years ago my father was trying to get a curtailment of his assignment in The Philippines to return stateside because of his new born daughter. His command denied the request. While playing Pinochle one evening, he told of his plight to the players at the table. A buck sergeant at the table told him to request again with right of review if denied. His request went up the chain to the Thirteenth Air Force where that same buck sergeant stamped approved and got the John Hancock of the commander. So in my father's case the highest rank was a simple buck sergeant.

5star general

5 Star general

If I remember correctly that would be an 05. Can't really remember of hearing of one though.

Secretary of the Army (civilian)