Ziyech was born in Dronten in the Netherlands. Between 2001 and 2007, he played for the youth academy of Reaal Dronten and ASV Dronten. In 2007, he joined the Heerenveen academy.

On 2 August 2012, Ziyech made his formal debut for Heerenveen in the first leg of the third qualifying round of the Europa League, against Rapid București, playing a total of 53 minutes before being substituted. He made his Eredivisie debut for the club on 10 August, in a 0–2 loss to NEC. Ziyech scored his first goal for Heerenveen in a 2–0 win over NAC Breda, on 10 August 2013. On 23 August, Ziyech provided two assists in a 3–3 draw with Ajax. On 8 November, Ziyech scored and provided an assist in a 5–2 win over Waalwijk. On 18 December, Ziyech scored two goals against AZ Alkmaar, in the fourth round of the KNVB Cup, one in regular time and a last-minute penalty to draw level and take the game into a penalty shootout, but he missed his penalty and Heerenveen were knocked out 6–5 on penalties. On 21 December, Ziyech scored twice and provided one assist in a 5–1 away win over AZ Alkmaar. On 18 January 2014, Ziyech scored in a 2–2 draw with Roda. On 9 February, he scored in a 3–1 win over Groningen. On 27 April, Ziyech scored once and provided an assist in a 4–1 win over Utrecht, after coming on as a substitute.

On 18 August 2014, Ziyech joined Twente for €3.5m, signing on a three-year contract and taking the number 10 shirt. On 5 October, Ziyech scored once and provided an assist in a 2–2 draw with AZ Alkmaar. On 6 March 2015, Ziyech scored twice in a 2–2 draw with Willem II. On 10 May, he provided three assists in a 3–0 home win over Dordrecht. On 17 May, Ziyech scored twice and provided an assist in a 3–1 away win over his former club Heerenveen. Ziyech finished the season with 11 goals and 15 assists in the Eredivisie. For the 2015–16 season, Ziyech was selected as captain of the club; however, he was stripped of the captaincy in early January 2016, after he made disrespectful comments against the club and publicly requesting a transfer. The 2015–16 season was the most prolific season in Ziyech’s career, as he scored 17 goals and provided 10 assist in the Eredivisie.

Ziyech was originally eligible to play for the national teams of the Netherlands, where he was born and raised, or the land of his heritage, Morocco. He played for Dutch national youth teams, playing for the U19s, U20s and U21s. He received his first call-up to the senior squad in May 2015, for friendly matches against the United States and Latvia.

In September 2015, Ziyech confirmed his choice to represent Morocco on the international stage. Ziyech made his debut for the national team on 9 October, in a 1–0 defeat to the Ivory Coast. On 27 May 2016, he scored his first two goals for Morocco, in a 2–0 win over Congo. On 4 September, Ziyech scored in a 2–0 win over São Tomé and Príncipe in a 2017 Africa Cup of Nations qualifying match. Ziyech was not selected for the final 23-man squad for the 2017 Africa Cup of Nations.

On 30 August 2016, Ziyech signed for Ajax on a five-year deal, with a reported transfer of €11m. On 15 September, Ziyech was given a red card in the 79th minute, in a 2–1 win over Panathinaikos in the opening group game of the Europa League. Six days later, on 21 September, he scored his first goal for Ajax in a 5–0 win over Willem II in the KNVB Cup. On 2 October, Ziyech scored his first league goal for the club in a 3–2 win over Utrecht. On 20 October, he scored in a 2–2 draw with Celta Vigo in the Europa League. On 20 October, he scored in a 1–0 win over Excelsior. On 3 November, Ziyech scored in the reverse fixture against Celta Vigo in the Europa League, a 3–2 win. On 4 December, he scored a penalty in a 2–0 win over Groningen. On 15 January 2017, Ziyech scored twice in a 3–1 away win over Zwolle. On 29 January, he scored in a 3–0 win over Den Haag. On 8 April, he scored in a 5–1 away win over NEC.

On 12 August 2017, Ziyech scored the opening goal in a 1–2 defeat to Heracles Almelo. On 20 August, Ziyech scored in a 3–1 win over Groningen. On 9 September, Ziyech missed a penalty but eventually scored just five minutes later in a 3–0 win over Zwolle. On 18 November, Ziyech provided an assist in an 8–0 win over NAC Breda. On 26 November, he provided an assist in a 5–1 win over Roda. On 14 December, Ziyech scored in a 3–1 win over Excelsior. On 20 December, Ziyech missed a penalty against his former club Twente, in the round of sixteen of the KNVB Cup, with Ajax suffering elimination after losing the penalty shootout. On 4 February 2018, Ziyech scored an injury-time goal in a 3–1 win over NAC Breda. Three days later, on 7 February, he scored in a 4–2 away win over Roda. On 18 March, Ziyech scored twice in a 5–2 away win over Sparta Rotterdam. On 19 April, Ziyech scored in a 4–1 win over Venlo.

On 1 September 2017, Ziyech scored in a 6–0 win over Mali, in a qualifying match for the 2018 FIFA World Cup. He was selected for the final 23-man squad for the 2018 FIFA World Cup.

On 25 July 2018, Ziyech scored in a 2–0 win over Sturm Graz in the second qualifying round of the UEFA Champions League. On 22 August 2018, Ziyech scored in a 3–1 win over Dynamo Kyiv in the play-off round of the UEFA Champions League. On 13 February 2019, he scored his first Champions League goal, scoring the equaliser in a 1–2 loss against Real Madrid in the round of 16. On 5 March 2019, he scored again in the 4–1 victory over Real Madrid in the second leg, which saw the title holders being knocked out and bringing Ajax to the quarter-finals, where they eliminated Juventus to reach the semi–finals of the competition.

On 30 April 2019, Ziyech assisted for the only goal in the Champions League semi–final first leg win at Tottenham Hotspur. He also scored the second goal for Ajax in the second leg of the semi-final, where Ajax were beaten 3–2 by Tottenham and were knocked out of the tournament on away goals with a 3–3 aggregate score. In August 2019, he signed a new three-year contract with Ajax.

On 14 February 2020, it was announced that Ajax and Chelsea had reached an agreement for the transfer of Ziyech for a fee of €40 million (potentially increasing to a maximum of €44 million, with variable factors). He joined the Premier League club for the 2020–21 season. Ten days later, Chelsea announced they had agreed personal terms with Ziyech and that he had signed a five-year contract. Ziyech made his league debut for Chelsea on 17 October 2020, in a 3–3 home draw against Southampton after he came off from the bench. On 28 October 2020, he scored his first Chelsea goal in a 4–0 away win over Krasnodar on matchday two of the Champions League. Three days later, Ziyech started his first league match for Chelsea, contributing with a goal and an assist in a 3–0 away win over Burnley. In doing so, Ziyech became the first Chelsea player since Diego Costa to score in his first two starts for Chelsea in all competitions. In Chelsea’s next league match, Ziyech provided two assists and was named the man of the match as Chelsea defeated Sheffield United by a score of 4–1.