Yes, quite a few in fact. A bit too many to sum up in this post, but I'll list some notable examples. Firstly, it must be acknowledged that comparative mythology delves into common human experience, emotion, and psychology. Joseph Campbell stated, "myths are public dreams, dreams are private myths." Comparative mythology draws on similarities of the human conscious and subconscious being and displays them symbolically though cultural narratives; since the human psyche mostly functions in similar ways across the globe, civilizations without contact often developed similar narratives.
You mentioned the universal flood myth, probably originating from receding glacial ice sheets in the Late Quaternary and the subsequent Black Sea deluge. During this relatively rapid event, ancestral cultures of many Eurasian civilizations, the Indo-Europeans, experienced this cataclysmic flood which eradicated many of their coastal villages. The plethora of factions heralding from Indo-European linguistic roots went on to tell stories of this great flood, influencing centuries of Eurasian generations to come.
However, your question specifically asked for disparate cultures' similar myths, for an influential historical event such as the Black Sea flood can permeate so many religions, it may be hard to pinpoint a source.
As aforementioned, Campbell's ideas of comparative mythology deal with common human psychology and narrative development, and many separate cultures brewed strikingly similar tales.
Here are a few examples:
Certainly, the flood stories of the Indo-Europeans did not reach the ears pre-Columbian Mesoamerican civilizations. Their flood myths evolved separately from Eurasia, but hold similar significance nonetheless.
Not only did Khnum and Prometheus mold humanity from clay in Egytian and Greek mythology, the Chinese mother goddess did so as well. I doubt transcontinental contact had been established in the Bronze Age, but this one I'm not entirely sure about. This goes for all other examples, but correct me if two myths might be related through cultural contact.
Dragons and reptilian monsters are fairly ubiquitous, with both feared Western dragons of Europe and venerable Eastern dragons of Asia developing with independent symbolism. Many other cultures had semi-dragon-like beings in their mythologies, such as the Rainbow Serpent of the Aborigines, the mo'o of the Hawaiians, Kukulkan of the Maya, and Kirimu of the Nyanga.
Giants are a staple of world mythology something about the towering might of long-lost lumbering ancestors, from the Greek giants and titans and Nephilim of Abrahamic faiths, to the Quinametzin of the Aztecs. (Side note: another motif is the "four pillars of the sky," wherein four giants, or dwarves, uphold the four corners of the earth; this can be found in Aztec, Norse, and other Eurasian myths)
There are numerous other myths, and I will link a few here, including Chaoskampf, Axis Mundi, the destruction of a primordial to create earth (see Ymir), the typical concept of good vs. evil popularized in the West by Zoroastrianism, the universal creation of land and life out of chaos and nothingness, and Apocatastasis (also prominent in Mesoamerican myths).
As you can tell, I tried to focus on myths separated by geographical impediments (Indo-Europeans influenced cultures from Scandinavia to India, so most popular mythologies share similar roots, and I tried to steer clear of relating those according to the question's stipulations), and despite those, many myths seem ubiquitous. This fascinating subject of comparative mythology is explored wonderfully by Joseph Campbell's work, and I highly recommend looking into his research for further studies.
Thanks for reading. Have a wonderful day.
