Douglas-fir is the English name applied in common to evergreen coniferous trees of the genus Pseudotsuga in the family Pinaceae.
There are five species, two in western North America, one in Mexico, and two in eastern Asia. The Douglas-firs gave 19th century botanists problems due to their similarity to various other conifers better known at the time; they have at times been classified in Pinus, Picea, Abies, Tsuga, and even Sequoia. Because of its distinctive cones, Douglas-firs were finally placed in the new genus Pseudotsuga (meaning "false Tsuga") by the French botanist Carrière in 1867. The genus name has also been hyphenated as Pseudo-tsuga.