Kai Kazmirek (born 28 January 1991) is a German track and field athlete who competes in the decathlon.

He also competed in the combined events youth championships, coming seventh outdoors and fourth indoors.

[3] The year after he won the German junior heptathlon title and improved his decathlon score to 7829 points.

[3] Kazmirek improved to 8350 points at the Ratingen meeting in 2013 and followed this up with an 8366-point best to win the gold medal at the 2013 European Athletics U23 Championships.

This earned him his first senior international selection and he improved further at the 2014 IAAF World Indoor Championships, taking sixth overall with a total score of 6173.