The new flights will start in October.
The Russian airline has been operating a daily service between the UK and Kalingrad since last June.
These are cheap flights, with prices starting at £200 for a return ticket. These prices are inclusive of taxes and surcharges.
Loretta Durell, KD Avia’s UK sales manager, said Yekaterinburg is an important new destination and is popular with tourists owing to its museums, art galleries and theatres.
"However it is perhaps most famous as the place where the family of Nicholas II were executed in 1918," she added.
"It is also Russia’s fifth largest city and has many business links to the UK."
Yekaterinburg has a population of 1.2 million and was established in the early 18th century.