The following is a list of Sites of Special Scientific Interest in the Western Isles North Area of Search. For Western Isles South see List of SSSIs in Western Isles South. For SSSIs elsewhere in Scotland, see List of SSSIs by Area of Search.
- Achmore Bog
- Cnoc A'Chapuill
- Flannan Islands
- Glen Valtos
- Gress Saltings
- Little Loch Roag Valley Bog
- Loch A' Sgurr Pegmatite
- Loch Dalbeg
- Loch Laxavat Ard and Loch Laxavat Iorach
- Loch Meurach
- Loch na Cartach
- Loch nan Eilean Valley Bog
- Loch Orasay
- Loch Scarrasdale Valley Bog
- Loch Siadar
- Loch Stiapavat
- Loch Tuamister
- Luskentyre Banks and Saltings
- Mangersta Sands
- North Harris
- North Rona and Sula Sgeir
- Northton Bay
- Port of Ness
- Shiant Isles
- Small Seal Islands
- Stornoway Castle Woodlands
- Tob Valasay
- Tolsta Head
- Tong Saltings