A flexible downspout connector apparatus includes a flexible extension pipe, and a first adapter member and a second adapter member, both nested together at one end of the pipe. The first adapter member includes a connection portion for connecting to a downspout outlet end of a first size, and the second adapter member includes a connection portion for connecting to a downspout outlet of a second size. The second adapter member is releasably telescoped with respect to the first adapter member and may be left in place or removed at the option of the user to accommodate for different downspout outlet end sizes.