Abstract: A collapsible trailer to be towed by a bicycle has front and rear U-shaped members pivotally mounted on an axle to the ends of which wheels can be attached. The front and rear portions of front and rear floor panels pivotally mounted on the axle are suspended from the front and rear U-shaped members, respectively, by tension members when the trailer is open for use but can be pivoted toward each other when the trailer is collapsed. A forward extension of the front U-shaped member can be connected to a bicycle so the trailer can be towed. Foldable front, side, and rear panels, which can enclose or be attached to or comprise the tension members, combine with the floor panels to form the body of the trailer.