John Grey, 2nd Baron Grey of Wilton (d. 28 October 1323) was an English nobleman and administrator.
He was the son of Reginald de Grey, 1st Baron Grey de Wilton and his wife Maud de Verdun (or Maud daughter and heir of William Baron FitzHugh). His first office was as vice-justice of Chester from 1296 to 1297.
He participated in the siege and capture of Caerlaverock Castle in July 1300. During the siege the English heralds composed a roll of arms, the Roll of Caerlaverock, in the form of verses of poetry, each describing the feats of valour of each noble and knight present, with a blazon of his armorials. In the Caerlaverock Poem at K 62, Grey's arms are recorded as BARREE silver at the Asur entaillie o bende red engreellie. His arms are blazoned in two additional ancient sources: The Galloway Roll, GA 104 (Sir Jehan de Grey, barre d'argent et d'asur a une bende engreslee de gueules); and St George's Roll, E 141 (Joan de Grey Barry of six argent and azure a bend indented gules). Whether the bend was engrailed or indented in the early 14th century is not significant to modern heralds because no descendant was recorded as displaying it. Since at least the 19th century his arms have been blazoned: Barry of six argent and azure overall a bend indented gules, while his descendent "Lords Grey of Wilton" displayed: Barry of six argent and azure in chief three torteaux over all a label of three points argent, i.e. Grey of Codnor (the more senior branch of the family) with a white label (as a canting reference) for difference.
He was summoned to Parliament from 1309 to 1322. His first parliamentary appointment was that of Lord Ordainer in 1310, and was followed by the grant in 1311 of Ruthin Castle, which passed to his younger son Roger de Grey. He was at the Battle of Bannockburn, where the English army took a heavy defeat. Nonetheless he was trusted by Edward II who was confident in the appointment as Justice of North Wales in Feb 1314/15 and Governor of Caernarfon Castle. He was relieved of his constabulatory responsibilities the following year and called to raise troops in response to the insurrection led by Llywelyn Bren.