Yes, and we have a great deal of evidence on this. The level of distinction varied with the level of military and social organization within an ancient/pre-modern society. These distinctions, examples of command hierarchy, were a necessary development of military campaigning in an organized fashion, but also directly conformed to the social organization of any given ancient society.

My favorite ancient battle to examine is the Battle of Kadesh (1288 BCE/BC), because there is just so much we have available describing it. The Battle was fought between an Egyptian army under Ramesses II and a Hittite commanded army under Muwatalli II. [Wikipedia: Battle of Kadesh]

Let's look at the Hittites. Their military at Kadesh numbered some 40,000 Bronze-age infantry and 3,700 chariots. It was a warrior society, with the Great King expected to lead warriors into battle, and to be there to personally command his force. As the commander in chief and king, he was distinguished entirely by his royal garments. Members of the king's family often held other high ranking military positions, followed by members of the Hittite nobility, with titles such as 'Chief of the Bodyguards,' or 'Chief of the Standing Army Troops of the Right,' etc. They would have been distinguished by the same clothing and emblems in military service as in social rank.

However, "To judge from both Hittite and Egyptian reliefs, even the highest-ranking Hittite officers seem not to have stood out conspicuously from their troops, as far as battledress and equipment were concerned." [The Hittite Warrior by Trevor Bryce and published by Osprey, p. 18]

Hittite military organization was hierarchical, and the numbers were there, but most military units (as with other ancient militaries) were formed and recruited locally and regionally. A warrior from one region of Anatolia would not be placed in a unit with soldiers from another region. The Hittite Empire could not be described as cosmopolitan. As such, regional traditional dress was likely enough to distinguish both units and rank.

Move ahead some 900 years, and the Romans are a great and well known example of a well-organized, hierarchical military with rank and insignia denoting enlisted and officer classes. While not the first to make distinctions based on rank, they were certainly the first to do it on such a massive and detailed scale. These distinctions were a reflection of the organization present in Roman civic society. Military organization on such a large and organized scale, within a hierarchical civic society, also had a highly-structured hierarchy of command, with insignia and rank, both for ceremony and distinction in battle. [Wikipedia: military ranks of ancient Rome]

But what about one of Rome's contemporary opponents? The Celts of the early Roman era (300 BCE/BC to 100 CE/AD) were a society structured by family, clan, and loosely organized tribe. Caesar's Gallic War is filled with accounts of these decentralized tribes. There were nobility, priests, free men and slaves, but society itself was far less structured than Roman society, and the Celtic military, such that it was, reflected that.

Personal combat was valued above all else, so leadership was often a front line activity. The military was also composed almost entirely of free men, while contemporary accounts describe slavery as being widespread in Celtic society, and as such, a Celtic army tended to be much more egalitarian than Celtic society itself. Warriors often displayed their wealth and status individually with jeweled and embroidered clothing. Roman accounts tell of richly-colored cloaks worn over mail shirts, with painted shields, long spears and helmets being common. There was also the practice of ritual nudity in battle, which may have complicated distinctions of rank and structure within a Celtic army. The army would have been organized along tribe, clan and family lines, with tribal kings, clan chieftains and heads of families expected to lead. [Celtic Warrior: 300 BC - AD 100, Allen & Reynolds, Osprey]

Military organization then, nearly always conforms to the structure of social organization, in the ancient world as now. As society became more centralized, more specialized and more complex, so did rank and insignia become more specific and distinct.