Koos may refer to:
Koos (name), a masculine given name and a surname
Koos (fashion label), a former haute couture fashion label
Koos (island), in the Bay of Greifswald, Mecklenburg-Vorpommern, Germany
Koos Group, a Taiwan-based pan-Asian business group
KOOS, a radio station in North Bend, Oregon, United States
KTEE, originally KOOS, a radio station in North Bend, Oregon
Koos/Together, an Estonian political party
