Not from the other side of a wide-area network, but if they are continuously in close proximity to you, or can effectively monitor everywhere (three letter agency), then yes. Of course, there are other ways to track you.
I think this is only true for older mobile networks. In 4G and 5G, I don't think the IMEI is part of any unencrypted radio message anymore.
Even the IMSI is only used when absolutely necessary, i.e. for the initial attachment procedure when cold starting a device or entering a new routing area; after that, it's replaced by an alias called TMSI to make tracking phone users a bit harder.
New Android versions will supposedly have a switch in their settings to show a warning every time the IMEI or IMSI is transmitted in plantext [1].
