By what denominational name are the Puritans known today?

The term Puritan ceased being used not long after the mid-17th century in the U.S., but in its original form, English and then American Puritanism was closest to original Presbyteranism as practiced by John Knox and his followers in Scotland. The Presbyterian Church was, in turn, based on Calvinism. Presbyterianism remains alive and well in the U.S.

The Congregationalists are also descendants of the Puritans, though in the 19th century, many Congregational Churches merged with other groups to form the United Church of Christ in the U.S. (Some did remain separate and are still influential in New England.)

Puritanism in the U.S., by the way, had an influence on virtually all of our Protestant denominations, including Episcopalianism, despite the latter's relationship with the Church of England.


https://en.wikipedia.org/wiki/Puritan

I'll just add (as by coincidence they were mentioned on TV tonight) the Plymouth Brethren may be the closest group to the original puritans, eschewing all modern technology as well as contact with outsiders (though they do live amongst the wider community). I can't think of any other group closer to them.