Yes, but that depends on your definition of Germany. The modern German nation (founded in 1871) was a monarchy until 1918, however it was termed "empire" not "kingdom" and had an emperor. Rather it was a federation of German states, some of which were indeed kingdoms like for example the Kingdom of Prussia (the King of Prussia also bore the title Emperor of the Germans) or the Kingdom of Bavaria. So, even fewer than a hundred years ago, there were German kings.

But I'll guess you are asking if there ever was a Kingdom of Germany such as the Kingdom of France, the Kingdom of England or likewise. If so, the answer is no. At least not a kingdom in any way like these kingdoms. All of what we would consider Germany today was from the early Middle Ages on, throughout the early Modern Era, until 1806, part of the Holy Roman Empire, a multi-national, multi-linguistic, comprehensive entity which eludes modern day definitions of a state.

The most prominent part of the Holy Roman Empire was indeed the regnum teutonicum, the Kingdom of Germany, alongside the regnum italiae, the Kingdom of Italy. This was a quite delicate structure and at this time (early to high Medieval) there was nothing really formalized about the power relations inside the Empire (which happened much later), and much was still in a constant state of flux (i.e. being subject to the power struggles between dynasties, lords, Emperor and Pope etc.). Back then, the Pope was supposed to crown German kings to be the Roman Emperor, and the title of German king was at times used as a propaganda tool against the bearer, separating him from the Roman crown. Thus, in the 12th century German kings began to adopt the title of rex romanorum ("King of the Romans") once elected by their peers to emphasize their claim for the Imperial crown. The rex teutonicorum fell out of use, the Kingdom of Germany never came to mean anything else than a subdivision of the Empire, and thus never developed along the lines of the kingdoms of, say, France and England, which arguably became proto-nations in the late Medieval/early Modern Era.