On 2 August 2019, Willems joined Newcastle United of the Premier League on a season-long loan deal with an option to buy. Willems scored his first goal for Newcastle and in the Premier League on 14 September, putting the Magpies into a shock lead at reigning UEFA Champions League winners Liverpool but the side eventually fell to a 1–3 defeat. Willems then scored in a 2–2 draw with reigning league champions Manchester City on 30 November.