I previously lived in the UK for 5 years before leaving. Can I apply for Settled Status, using those years against my application?
Yes. If you lived in the UK for at least 5 years continuously but you’ve not been away from the UK for more than 5 years since then (see also this FAQ on settled status 5-year absences). You qualify for Settled Status based on your historic residence .
You can read more about this on Settled’s website.