Kim took two years of college in Seoul, Korea as a French literature major, before transferring to Dartmouth College in 1955. Soon after, at Dartmouth, he changed to a combined major in French, mathematics, and philosophy and received a B.A. degree. After Dartmouth, he went to Princeton University, where he earned his Ph.D. in philosophy.

Kim is currently the William Herbert Perry Faunce Professor of Philosophy at Brown University (since 1987). He has also taught at Swarthmore College, Cornell University, the University of Notre Dame, Johns Hopkins University, and the University of Michigan, Ann Arbor. From 1988 – 1989, he was president of the American Philosophical Association, Central Division. Since 1991, he has been a fellow of the American Academy of Arts and Sciences. And, along with Ernest Sosa, he is a joint editor of the quarterly philosophical journal Noûs.

According to Kim, two of his major philosophical influences are Carl Hempel and Roderick Chisholm. Hempel, who sent him a letter encouraging him to go to Princeton, was a "formative influence". More specifically, Kim claims that he hopes he learned "a certain style of philosophy, one that emphasizes clarity, responsible argument, and aversion to studied obscurities and feigned profundities." From Chisholm he learned "not to fear metaphysics." This allowed him to go beyond the logical positivist approaches, that he had learned from Hempel, in his investigations in metaphysics and the philosophy of mind.

Kim's philosophical work focuses on the areas of philosophy of mind, metaphysics, action theory, epistemology, and philosophy of science.

Kim has defended various mind - body theories during his career. He began defending a version of the identity theory in the early 1970s, and then moved to a non-reductive version of physicalism, which relied heavily on the supervenience relation.

More recently, he has rejected strict physicalism on the grounds that it is an insufficient basis for resolving the mind - body problem. In particular, he has concluded that the hard problem of consciousness -- according to which a detailed and comprehensive neurophysical description of the brain would still not account for the fact of consciousness — is insurmountable in the context of a thoroughgoing physicalsim. His arguments against physicalism can be found in his two latest monographs: Mind in a Physical World (1998) and Physicalism, or Something Near Enough (2005). Kim claims "that physicalism will not be able to survive intact and in its entirety." This, according to Kim, is because qualia (the phenomenal or qualitative aspect of mental states) cannot be reduced to physical states or processes. Kim claims that "phenomenal mental properties are not functionally definable and hence functionally irreducible" and "if functional reduction doesn't work for qualia, nothing will" Thus, there is an aspect of the mind that physicalism cannot capture.

Kim currently defends the thesis that intentional mental states (e.g., beliefs and desires) can be functionally reduced to their neurological realizers, but that the qualitative or phenomenal mental states (e.g., sensations) are irreducibly non-physical and epiphenomenal. He, thus, defends a version of dualism, although Kim argues that it is physicalism near enough. As of March, 2008, Kim still sees physicalism to be the most comprehensive world view that is irreplaceable with any other world view.

In a 2008 interview with Korean daily newspaper Joongang Ilbo, Kim stated that we must seek a naturalistic explanation for mind because mind is a natural phenomenon, and supernatural explanation only provides "one riddle over another". He believes that any correct explanation for the nature of mind would come from natural science rather than philosophy or psychology.

Kim has raised an objection based on causal closure and overdetermination to non-reductive physicalism.

Physicalism, according to Kim, has a principle of causal closure according to which every physical event is fully accountable in terms of physical causes. This seems to leave no "room" for mental causation to operate. If our bodily movements were caused by the preceding state of our bodies and our decisions and intentions, they would be overdetermined. It should be noted that mental causation in this sense is not the same as free will, but is only the claim that mental states are causally relevant.

Kim's work in metaphysics focuses primarily on events and properties.

Kim developed an event identity theory, but has not defended it recently. This theory holds that events are identical if and only if they occur in the same time and place and instantiate the same property. Thus if one waves ten fingers, several events occur, including the waving of an even number of fingers, the event of waving fingers that are evenly divisible by five, and evenly divisible by ten. Some have criticized his theory as producing too many events.

Kim also theorized that events are structured. He is known for a property - exemplification account of events. They are composed of three things: Object(s), a property and time or a temporal interval. Events are defined using the operation [x ,P, t].

A unique event is defined by two principles: the existence condition and the identity condition. The existence condition states "[x, P, t] exists if and only if object x exemplifies the n-adic P at time t". This means a unique event exists if the above is met. The identity condition states "[x, P, t] is [y, Q, t`] if and only if x=y, P=Q and t=t`".

Kim is a critic of the "naturalized" epistemology popularized by Willard Van Orman Quine in the latter half of the twentieth century. Kim's influential article "What is 'Naturalized Epistemology'?" (1988) argues that "naturalized" epistemologies are not proper epistemologies as they are merely descriptive in scope, while one generally expects an "epistemology" to make normative claims about knowledge. Kim claims that epistemology requires normative nature, and mere description cannot account for justified belief. Naturalized epistemology cannot address the issue of justification, and therefore it does not share the same aspiration as the traditional approach to epistemology. The status of descriptive belief remains as belief, not knowledge. As such, naturalized epistemologies cannot be used to answer many of the questions one would expect theories of knowledge – epistemologies – to resolve.