"...if you want to know what your future looks like, don't waste your time on Analog; read Time magazine. We are already saturated in the future. "
- Peter Watts

Or earlier in this article Present Inefficiency in the Jury System in The Law Magazine, Or, Quarterly Review of Jurisprudence (1849):

While therefore we would desire our juries to be moulded after a higher standard, we do not mean that we want in them a superior degree of particular, partial or artificial intelligence, but a legal guarantee for greater general and judicial talent.

The Oxford English Dictionary lists the following proposal as the first use of the phrase "artificial intelligence":

"A Proposal for the Dartmouth Summer Research Project on Artificial Intelligence" authored by John McCarthy [credited with coining the phrase], Marvin Minsky, Nathaniel Rochester, and Claude E. Shannon.

The proposal aimed to study if machines could use language, form abstractions and concepts, solve kinds of problems now reserved for humans, and improve themselves.

The conference was actually held from June 19 to August 16, 1956, at Dartmouth College; widely recognized as the birth of AI as a field of study.

It took a while to catch on in the sf community. Frank Herbert used it in Dune Messiah in 1969:

...Eleven lights in the fencing prisms! That brainless automaton loomed in his mind with all the aspects of an ancient horror creature. Its possession was the shibboleth of this age, but it carried also the taint of old immorality. Once they had been guided by an artificial intelligence, computer brains. The Butlerian Jihad had ended that, but it hadn’t ended the aura of aristocratic vice which enclosed such things.