Yes, definitely. If you do a quick search of trademarks on the USPTO website using “.COM”, you see thousands of such trademarks, reflected in both both pending applications and registered trademarks.
There are a few subtleties to note, however.
It is fundamental that a trademark cannot be registered until it is used in commerce to market goods and services. What may not be readily apparent is that registering a domain name alone is not use of the trademark in commerce for the purposes of acquiring trademark rights. What is even less apparent is that using the domain name to point to a website selling or advertising goods and services may also not be use of the trademark in commerce for the purposes of acquiring trademark rights unless certain rules are followed.
Thus, in a hypothetical example, if a website “www.joewear.com” points to a website for selling clothes that are unbranded or are well known national brands, but there is no mention of “www.joewear.com”, no trademark rights in the domain name are acquired. What's more, in such a case, no trademark rights accrue in the related word mark, “JOE WEAR” unless “JOE WEAR” is branded on merchandise or prominently displayed on the website in association with forms or other means for buying goods and services.
More confusion … where “www.joewear.com” points to a website selling merchandise prominently branded “JOE WEAR”, but not displaying the literal text “www.joewear.com” on the website or on merchandise, trademark rights accrue in “JOE WEAR”, but not “www.joewear.com”. It then follows that where “www.joewear.com” points to a website selling merchandise prominently displaying the literal text “www.joewear.com”, but not displaying the literal text “JOE WEAR” on the website or on merchandise, trademark rights accrue in “www.joewear.com”, but not “JOE WEAR”.
Just to complicate matters further, however, where trademark rights have accrued in “JOE WEAR”, there's at least some argument to be made that if a competitor brands merchandise “www.joewear.com” or even “www.joe-wear.com”, there is a likelihood of confusion with “JOE WEAR”, and thus, there is trademark infringement.
One more bit of confusion, if a competitor simply registers “www.joe-wear.com”, the domain registrati0n is not, per se, an infringement of either “JOE WEAR” or “www.joewear.com”, but that is another topic altogether.
As a pure business consideration, word marks such as “JOE WEAR” are usually far more important and desirable than trademarks than domain names like “www.joewear.com”. Using domain names as trademarks may only be desirable in cases where …
1.) The website associated with the domain name is the product or service itself, and you want the public to identify your company with a very specific domain name.
2.) You think “.COM” something is a cool brand and you want to mark your merchandise as such.
If you really, really want to register a domain name as a trademark, there are a couple of simple rules to follow.
1.) Put the literal text of the domain name on every page of the website.
2.) Make sure the literal text of the domain name in closely associated with the means for buying the associated goods and/or services.
3.) In the case of hard merchandise, prominently display the literal text of the domain name on the merchandise itself.
If you have any questions, feel free to contact me.