Jetro Danovich Sexer Willems (born 30 March 1994) is a Dutch professional footballer who plays as a left wing-back or left-back for Segunda División club Castellón.

During his time with Sparta he progressed through the club's youth academy and made his senior debut on 16 January 2011, in a match against Go Ahead Eagles.

Although being young and quite inexperienced, Willems quickly showed evidence of his raw talent, especially his technique and attacking traits.

[14][15][16] Willems made 29 appearances during the 2017–18 season,[17] which included the surprise win over Bayern Munich in the German Cup final.

[19] On 2 August 2019, Willems joined Newcastle United of the Premier League on a season-long loan deal with an option to buy.

After almost a year of rehabilitation, Willems re-joined the group training of Eintracht Frankfurt at the beginning of 2021, but did not make any appearances for the rest of the season.

[citation needed] Willems left Eintracht Frankfurt after his contract expired at the end of the season.

In August 2021, Willems signed a two-year contract with newly promoted Bundesliga side Greuther Fürth and has been given the number 15 jersey.

[28] On 25 July 2024, Willems signed for Spanish Segunda División side Castellón, after a trial period.