Mysterious Traveller is the fourth studio album by the jazz and jazz fusion ensemble Weather Report, released in 1974. This was their final recording with founding bassist Miroslav Vitouš, who left due to creative differences. Vitouš was replaced by Alphonso Johnson. Another addition to the line-up is drummer Ishmael Wilburn. Greg Errico was the drummer for the tour between the previously released Sweetnighter and this album, but declined an invitation to be a permanent member of the band.

The record is the band's first that predominantly uses electric bass and incorporates liberal uses of funk, R&B grooves, and rock that would later be hallmarked as the band's "signature" sound. Also, the more restricted compositional format became evident on this album, replacing the more "open improvisation" formats used on the first three albums. It was voted as the album of the year by the readers of DownBeat for 1974, garnering Weather Report's second overall win in that category, also garnering a five-star review from that publication along the way. The Penguin Guide to Jazz Recordings included the album in its suggested “core collection” of essential recordings.