 At the World championships in Stuttgart Stewart finished eighth in the 100 m, in a time of 10.18 s.

At the World Championships in Gothenburg Stewart again finished eighth, in 10.29 s. The 4 × 100 m relay team anchored by Stewart finished fourth in 39.10 s. Stewart had made the 100 m final of four consecutive World Championships, the first two of which were spaced four years apart.At the January Boston Indoor Games Stewart finished third in the 60 m, in 6.72 s.

Competing in his fourth Olympics, Stewart recorded 10.18 s in his quarter final heat of the 100 m, a time insufficient to move him to the semi finals.Emmanuel Tuffour of Ghana received the final qualifying spot for the semi finals with an identical 10.18 s. Stewart ran the anchor leg in 9.14 s for the 4 × 100 m relay, the team recording a time of 38.81 for fourth place in its semi final.