In 1937, Mitchell-Innes was replaced as captain of Oxford by Sandy Singleton, and missed the start of the cricket season as he was busy studying. He did not play his first match until the middle of June, when he scored 137 and 66 not out against Leicestershire; his first innings total being described as "by far the best seen at Oxford this year." Later in the month, he scored another century to help Oxford chase 347 runs in the fourth innings of the match to beat Sussex. In the lead up to the University match, Mitchell-Innes was "regarded as the outstanding batsman of the two sides" by "The Times", but he did not bat well in the first innings, and was out for 19 runs. In the second innings, he fared a little better, scoring 29 runs to help Oxford to a seven wicket victory; their only win in the University match during Mitchell-Innes' time at Oxford. He topped the batting averages for Oxford once again, scoring his 630 runs at an average of 57.27. In all, during his four years at Oxford, he scored 3,319 first-class runs, a record for the university, at an average of 47.41.