He made his Test debut for England against New Zealand in May 2015 and scored his first Test run off the first ball of the game. He failed to make a significant score in either innings, being dismissed for just seven in the first innings and then losing his wicket while on 12 in the second. Despite this, England went on to win the game by 124 runs to go 1–0 up in the series. In the second Test, Lyth top scored for England with 107, helping them to post 350. However, he could not follow this up in the second innings, being dismissed for 24 as England lost the game by 199 runs to draw the series 1–1.