The first citation in the Oxford English Dictionary (which is pretty good about dating these things) under the 'advertisement' sense is from a 1933 issue of Fortune,

We used no media other than radio to feature this soup..using one-third of our commercials on Campbell's Chicken Soup.

The definition specifically mentions TV/radio broadcast, so it's unlikely that either the noun or a phrase like "commercial advertisements" predates radio.

That said, the word commercial was used as a noun in other senses before this one--the OED cites Dickens using the term to mean 'salesman' (as a clipped version of "commercial traveler"), and groups a meaning 'vagrant' under the same sense (dating to 1886).

Please note that the OED does its best to give the earliest attestations it can find, but their researchers don't have access to everything that was ever written in English, and obviously unrecorded conversations are lost to them forever. It's possible there's some document somewhere out there with an earlier attestation of the relevant sense of commercial than what the OED has, though it's unlikely that it's that much older.