From Longman Dictionary of Contemporary Englishmarket leaderˌmarket ˈleader noun [countable] BBTthe company that sells the most of a particular type of product, or the product that is the most successful one of its type the UK market leader in sports shoes
Examples from the Corpus
market leader• It will also become a market leader in several food areas within Scandinavia.• It is the recognized market leader in this field.• First Alert, the market leader, said the detectors were fine.• We must strike soon and become the market leader or some other company will seize the position.• As a consequence peat has been the market leader for the past forty years.• The Palm Pilot is currently the market leader with 75-80 % of the market share.• Kodak is still the market leader.From Longman Business Dictionarymarket leaderˈmarket ˌleaderMARKETING the company, product, or service with more sales than any other company, product etc in its marketThe company is the US market leader in petfood. → leader 