This junction was directly east of Dumbarton Central station. It was formed in 1896. Here the former Caledonian and Dumbartonshire Junction Railway of 1850 (now owned by the North British Railway) was met by the newly opened Lanarkshire and Dumbartonshire Railway.
The line through Dumbarton Central and on to Balloch Pier was conveyed to the newly created Dumbarton and Balloch Joint Railway (Caledonian Railway, Lanarkshire and Dumbartonshire Railway and North British Railway Joint). This caused a break in ownership of the North British Railway owned line from Glasgow Queen Street High Level to Fort William [1st].
The junction also included the approach to Dumbarton Joint Goods, which was approached from the east by either line. There was a small exchange yard. This short branch also served the MacMillans Shipyard (later Ballantyne Dumbarton Grain Distillery) and Denny Bros' Leven Shipbuilding Yard.
A goods loop ran from the west side of Dumbarton Central, on its south side, to the junction, where connections were made, and on to the south end of Dumbarton East on the new line.
Dumbarton Central station was rebuilt for the opening of the new line and joint ownership of the line to Balloch Pier.
The junction closed in 1960 when the original line east closed as far as the Bowling Oil Terminal sidings. Following closure the embankment of the original line's approach to the junction was landscaped. No obvious trace of it remains today near the former junction, but a landscaped footpath follows its course just to the east. Some sidings remain on the south side of the junction, in use as part of a permanent way depot.