XPS 15 9560 Ethernet Accessory

You could always purchase a USB-Gigabit Ethernet dongle.

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@Flembot95   Dell's "woeful accessory range" doesn't include an Ethernet adapter?  So you're not counting this one that you could plug into the XPS 15's USB-C port or this one that would plug into one of the USB-A ports if you wanted to keep the USB-C port free for other things?  There's also the DA300 if you want a mini-dock type of device that has Ethernet and some other connectivity, and as mentioned above, there are tons of third-party options too.

Thanks @jphughan However I expect Dell to allow the ethernet accessory to show up under "accessories" when I am on the support page for my device - but I could not find one there so I assumed Dell did not have one. Why oh why Dell's website is rubbish is beyond me. 

@Flembot95  I just went to the support.dell.com page for the XPS 15 9560 and clicked Parts & Accessories.  From there, if I clicked "PC Accessories" or "Pars & Upgrades", the DA300 was among the products listed.  Granted that may be more than you needed, but it's an accessory that includes Ethernet. I'm also pretty sure those types of accessories would have been listed in the Accessories section of the ordering page.  In any case, USB Gigabit Ethernet adapters have existed for quite a while now, and their compatibility is not limited to specific systems.  You don't actually need a Dell-branded adapter, and in fact unless you need some particular features where system support for a specific accessory is necessary (e.g. PXE boot), then you'd likely save money by going with a third party option regardless of whether Dell has an equivalent.  I'm sorry you didn't seem to realize that they existed, but at least you know you don't need to drag a docking station around.