A heat exchanger for a vehicle includes: a housing having an interior space; a header installed at one end of the housing and having a first fluid inlet manifold; a second fluid inlet manifold; and a second fluid outlet manifold; and a heat exchange core installed in the interior of the housing and having a plurality of core elements spaced apart from each other. The plurality of core elements are coupled to the header, and a plurality of first fluid passage, through which the first fluid passes, is respectively formed between the adjacent core elements. Each of the core elements has a second fluid passage, through which the second fluid flows, an inlet of the second fluid passage communicates with the second fluid inlet manifold, and an outlet of the second fluid passage communicates with the second fluid outlet manifold.