Floodplain lakes can support substantial fish recruitment, but river regulation has altered the pathways through which young fish disperse from these nursery habitats into broader river networks. We investigated the dispersal of juvenile golden perch (Macquaria ambigua) from the Menindee Lakes, a major floodplain nursery in Australia's Murray–Darling Basin, during a managed flow release. We acoustically tagged 300 golden perch and released them into the lower Darling–Baaka River downstream of Menindee Main Weir. Their movements were monitored for six months using a receiver array extending approximately 500 km through the lower Darling–Baaka and Murray river systems. Of the tagged fish, 263 were detected and 211 undertook substantial movements beyond the immediate release area. Most dispersing fish initially moved upstream towards Menindee Main Weir, despite being unable to pass the structure, and many subsequently reversed direction and dispersed downstream. Movement outcomes differed between release events. Fish released later in the managed flow pulse were more likely to disperse and, after reaching Menindee Main Weir, were more likely to move downstream. Larger fish were more likely to make an initial upstream movement, but body size had little influence on their eventual dispersal outcome. Five fish reached the Murray River system, including one subsequently detected in the Great Darling Anabranch. These findings demonstrate that regulated releases can maintain long-distance dispersal and recruitment connectivity from an important floodplain nursery even in the absence of overbank flooding. However, connectivity depended not simply on the production of juvenile fish or the presence of flowing water, but on hydrograph timing, behavioural pathways and the functional configuration of the river network.