He has been replaced by Christian Hartnagel, 34, who has worked at Lidl for 13 years in different management positions across the business, including regional director at Lidl Ireland.
Most recently, Hartnagel was responsible for sales and operations in his role as a board director for Lidl Austria.
Lidl said today that it is "extremely grateful for Ronny's contribution" throughout his tenure as Lidl Great Britain's chief executive - which was part of a 16-year career at Lidl - during which time he "steered the business forward through a transformative period which saw a significant increase in market share within the UK along with continuous sales growth".
The German supermarket group also said that Hartnagel will be tasked with growing the brand even further in the UK - including continuing with "ambitious investment plans which will see store numbers potentially more than double to 1,500 in the long term". The group currently operates fewer than 640 stores in England, Scotland and Wales.