The store, which specialises in pet care, gardening and agricultural supplies has been a landmark business in Cork city since it opened in 1978.
Whilst the city branch will cease trading next month, the Bandon and Mitchelstown stores will remain open.
In a statement, McLaughlin's stated that they wish to centralise operations in their Bandon headquarters.
"McLaughlin's of Ship Street, Cork will close its doors for the final time in March 2020 after serving the Cork community since 1978 and spanning three generations.
"The decision to close our Cork store comes on the back of increasing competitive market challenges and the decision to centralise our operations to our headquarters in Bandon.
"Bandon and our Mitchelstown store will continue to serve the County of Cork, and beyond like we have for the past 70 years."
The business took the opportunity to thank their loyal cohort of customers, saying it has been a pleasure to serve the people of Cork city.
"We are hugely grateful for the support of our longstanding and loyal customers here in our Cork store.
"There have been some truly great people (and some characters!) through these doors over the years, and we enjoyed serving every one of you.
"To you, all, thank you sincerely."
The business is currently having a closing down sale and will close next month.