Breoton/Briten/Bryten/etc so long as we allow for the exclusion of Ireland. But not such as will serve to conflate the two. The notion of Ireland and Britain as a single territorial unit is something of an anachronism, in the Anglo-Saxon context. But as to Britain generally speaking, and the framing of its territorial nature...

The Old English version of Bede's Ecclesiastical History begins "Breoton ist garsecges ealond ðæt wæs iugeara Albion haten" (Britain is a sea island that was earlier called 'Albion').

The Anglo-Saxon Chronicle begins "Brittene igland is ehta hund mila lang and twa hund brad. And her sind on þis iglande fif geþeode. Englisc and Brittisc and Wilsc and Scyttisc and Pyhtisc and Bocleden" (The island of Britain is eight hundred miles long and two hundred broad. And there are on this island five peoples - English, and British, and Welsh, and Scottish, and Pictish, and Book-Latin).

Note that in the ethnolinguistic listing above, "Irish" is not inherently omitted. "Scottas" is a descriptor which is applied to the Irish as well (whereas "Iras" and "Iraland" are almost unattested), and refers to Gaels generally. However, from a territorial standpoint, in the Ecclesiastical History in particular (which addresses the island's geographic context in some depth later on), "Breoten" is explicitly exclusive of the island of Ireland (or 'Hibernia', which Latin term serves as the basis for most Old English reference to it). And while Ireland receives titular mention in the opening section, Spain, France and Germany are mentioned, but Ireland omitted entirely, in describing Britain's geographic context. And it is clear enough from the ASC's description of the island that it is only the island of Britain which is addressed. Which is what we can expect. The proximity of the Island of Ireland to Britain did not imply their sharing a conceptual geographic sphere, from the standpoint of the Anglo-Saxon textual corpus.

So as to a single Old English term which serves to refer to the British Isles per se (i.e., Britain and Ireland), I know of none such.