The Cowboy Cup, named in honour of NSW Suburban Rugby Union Life Member, Ian "Cowboy" Ross, is an inter-divisional competition based on club championship points and finals series results.
| Year | Club | Division |
| 2017 | Petersham | Div 1 |
| 2016 | Blacktown | Div 4 |
| 2015 | Beecroft | Div 4 |
| 2014 | St Patrick's | Div 1 |
| 2013 | St Patrick's | Div 1 |
| 2012 | Balmain | Div 2 |
| 2011 | Hunters Hill | Div 2 |
| 2010 | Blacktown | Div 3 |