M1 iMac ethernet connection
Can I use ethernet on an M1 iMac?
iMac (M1, 2021)
Question marked as
Yes.
The base model is "Configurable with Gigabit Ethernet" and the other 2 models include Gigabit Ethernet (ethernet plug is in the power supply).
See the following from Take a tour: iMac - Apple Support
Gigabit Ethernet (RJ-45): Ethernet is built into the power adapter included with the 24-inch iMac with four ports. The 24-inch iMac with two ports comes standard with a power adapter without built-in Ethernet, but can be configured with Ethernet at the time of purchase. To use Ethernet, connect a router or modem to the Gigabit Ethernet port on the power adapter.