@Kavu if you have a white Sky hub there is a list in the My Sky app. On the older black hubs you can find a list in the hub's web interface interface at 192.168.0.1. Howver be careful as the lists show devices by the name the device gives the hub which you may not recognise especially if it comes up as "Unknown"
If you suspect someone you dont want has connected their devices to your WiFi change the WiFi password see https://www.sky.com/help/articles/find-and-change-your-wireless-password
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65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
