It is likely Ventry Lane and Ventry Street were named in honour of Baron Ventry who was born William Mullins, the son of Thomas Mullins, the first Baron Ventry. William Mullins played an instrumental role in getting the Act of Union through the Irish Parliament in 1800, for which his father was awarded a peerage. He succeeded to his father's title in 1824. Baron Ventry was close to Viscount Castlereagh. He died in 1827. We surmise this reflects gratitude among some in Belfast.
This is one of a number of streets off Dublin Road which commemorate pro-Union peers. The group includes Salisbury, Ashburne, Hartington, Pakenham and Apsley.
The lane was marked unnamed on Ordnance Survey maps of 1883-4. It was named as Ventry Lane in Slater's Directory of 1894.