Tim Dieck (born 7 April 1996) is a German competitive ice dancer that currently competes for Spain with Olivia Smart.

His parents, Martina and Frieder, are involved in figure skating as a coach and judge, respectively, and his sister, Dominique, formerly competed in ice dancing.

The following season, they debuted on the ISU Junior Grand Prix series, finishing ninth in Riga, Latvia and fifteenth in Gdańsk, Poland.

They were also assigned to the 2014 World Junior Championships in Sofia, Bulgaria, but were eliminated after placing twenty-seventh in the short dance.

[3] Assigned to two Junior Grand Prix events, they placed eighth in Ljubljana, Slovenia, and seventh in Aichi, Japan.

Competing in the Challenger Series (CS), Müller/Dieck finished tenth in September at the 2015 Nebelhorn Trophy – their first senior international – and eighth the following month at the 2015 Mordovian Ornament.

Müller/Dieck were included in Germany's team to the 2016 European Championships in Bratislava, Slovakia, but were eliminated after placing twenty-third in the short dance.

[9] In spring 2016, Müller/Dieck began training under Marina Zueva in Canton, Michigan, in addition to Schulz and Young in Dortmund.

They won gold at the NRW Trophy for the first time, and were the German national silver medalists for the second consecutive year.

NRW Trophy champions for the second time, they then won their fourth consecutive silver medal at the German championships.

They did not return to the Grand Prix, but won the inaugural Denis Ten Memorial Challenge and the Open d'Andorra, followed by becoming German national champions for the first time.

[10] Initially assigned to the 2021 Cup of China on the Grand Prix, upon its cancellation Müller/Dieck were reassigned to the 2021 Gran Premio d'Italia.

[20] The release was granted in December 2022, and it was announced that they would begin training in April 2023 in Montreal under Smart's longtime coaches Marie-France Dubreuil, Patrice Lauzon and Romain Haguenauer.

Following controversy around the criteria used to arrive at this result, on December 27 the Spanish federation announced that Smart/Dieck would instead be given the country's lone World Championship berth.