In October 2021, the Bloomberg Billionaires Index estimated Kühne's net worth to be US$36.2 billion, making him the richest person in Germany.

[3] As important shareholder of flag-carrier Lufthansa, main owner of Hapag-Lloyd and Kühne+Nagel, Kühne is one of the money elites of Germany with influence into politics and economic circles.

[8] In 1981, the year of his father's death, he had to sell 50% percent of the company for 90 million Deutsche Marks to the former Lorho group.

He bought the company back for 340 million marks in 1992, and put the Kühne + Nagel Agency on the stock market in 1994.

[12][1] In April 2020, Kühne upped his stake in shipping company Hapag-Lloyd to 30%, having previously owned 26% of the business, making him the largest shareholder.

In September 2022, the German state sold a large part of its Lufthansa shares as a result of the Covid crisis.

A spokeswoman for Kühne said they were happy to actively support the sales process of the "German Economic Stabilization Fund" (WSF).

[19][20] The Kühne family fortune was built from the systematic looting of the assets of European Jews by the Nazis.

[21] Klaus-Michaels's father August Kühne had already moved the Kühnes' private and business residence to Switzerland.

With an estimated personal fortune of approximately 14.2 billion US dollars in 2020, Kühne was ranked the 5th richest individual in Germany and 74th worldwide.

[27] As of December 2023, the Forbes List ranked Kühne as the 47th richest person in the world, with an estimated fortune of US$31.5 billion.

[29] As per Forbes list of The Richest People In The World, dated 8 MARCH 2024, Klaus-Michael Kuehne is ranked #32 with a net worth of $39.2 Billion.

In 2007, he was awarded the title of honorary professor by the Hamburg Senate for his construction of the Elbphilharmonie Concert Hall and sustained commitment to the development of logistics science in the city.

[40] In July 2018, Kühne announced in another interview with Sport Bild that he would no longer provide financial support to HSV in the future, describing the decision as "sustainable".

The listed Hamburg State Opera would be demolished to make way for a modern real estate project.