Arkengarthdale is a dale, or valley, on the east side of the Pennines in North Yorkshire, England. Running roughly northwest–southeast, it is The Valley of the Arkle Beck, and is the northernmost of the Yorkshire Dales. It is a subsidiary dale to Swaledale, which it joins at Reeth.
On its way up the dale from Reeth the unclassified road crosses many other small streams and their catchments, such as Great Punchard Gill, Roe Beck, Annaside Beck, and William Gill. It passes through several small settlements: Raw, Arkle Town, Langthwaite (where a narrow back road leads to Booze), Eskeleth and Whaw.
At Eskeleth Bridge another unclassified road forks northeast (towards Barnard Castle); this also joins a minor road running along the northern side of the dale to Whaw. Beyond Whaw is the most sparsely populated upper part of Arkengarthdale, which here runs roughly west–east. This area is one of the most northerly parts of the Yorkshire Dales National Park. Eventually the dale ends and the road reaches the Tan Hill Inn, the highest in England, just outside The Park, near the Pennine watershed.