This document is a fieldwork report for an archaeological trial trench evaluation, carried out by University of Leicester Archaeological Services (ULAS) at Oundle School (TL 04190 88260) in February 2020, in advance of the proposed redevelopment of the Grade II Listed Gascoigne Building. No other archaeological work was carried out within the proposed development area, however, historical sources suggested that the site may have been the location of a royal Saxon manor. For this reason, the site was designated by Historic England as a Scheduled Monument (No. 1006619). Three trenches were excavated within the footprint of the proposed development to provide preliminary indications of the character and extent of any heritage assets in order that the potential impact of the proposed development on such remains could be. Archaeological remains were identified in all three trenches, including pits, ditches, and extensive evidence of structural activity including post-holes and stone walls. The concentration of archaeology in all three trenches was high and the preservation was, overall, quite good. The remains were likely to represent habitation and associated domestic and iron working activities of Saxon and medieval date. The archive for the site will initially be held by ULAS and will be transferred, with accession number ENN109826, to the Northants ARC as soon as the facility becomes available.