Ireland for the most part was off of Hitler's radar, so to speak. The Irish were officially neutral during the war, and pre-war they fell outside his areas of interest. They weren't part of his plans to undo Versailles, create a German dominated economic union, or part of his "living space" in Eastern Europe. So they simply just don't come up in Mein Kampf or his pre-war speeches.

Once he realized the British weren't going to drop out of the war in mid-1940, he did take note of the island. The Irish, while neutral, had an antagonistic relationship with the British. So they were a potential ally. He had the Heer develop an operation plan, "Green" to invade Ireland. But the plan never seemed to gain traction. At times it was considered a diversion prior to executing an invasion of England. Sometimes it was considered a follow up. Sometimes it was considered a stand alone operation. At times it was suggested it only be executed if invited by the Dublin government. Other times it was suggested it be used if the Dublin government fell or ceased to be neutral. It was a plan that no one seemed able to decide if, how, or why it should be executed. And officers like Admiral Raeder considered it an entirely unworkable concept in light of the existence of the RN and RAF.

In any case Hitler's real interest lay to the East. Operation Green remained in existence throughout the war, and was occasionally updated. But there was never a serious push to implement it. And if the UK had ever agreed to peace terms, it would have been shelved entirely.

That was fantastic, thank you. I know some Irish from the Republic joined the ulster rifles and British forces and when Belfast was bombed firefighters etc from republic came up to help . not totally neutral ☺