His career highlight came when Robin Of Navan won the Group One Criterium de Saint-Cloud in 2015, while the likes of Knight To Behold, Fighting Irish, Classic Remark and Festoso won black type races for him. The Lambourn handler also trained subsequent Melbourne Cup winner Green Moon in his early career.
Dunlop, son of former Arundel-based trainer John and brother to Classic-winning handler Ed, is looking to stay in the racing industry if possible.
"It is something I have thought about over the last few years and my main reason is that it is so hard to keep a business thriving in the current economic climate," he said in a statement posted on Twitter.
"When you don't have a huge string of horses to cover the rising costs of staff, transport, feed, bedding, it is just not viable.
"Thankfully my business is in good shape, so I thought this was a good time to make this decision and to look for a new career.
"We have had some wonderful horses and clients over the years and many memorable days racing.
"I am going to be looking at future job options within the racing industry and beyond, which is very exciting.
"I would like to thank my current team at Frenchmans Lodge Stables who have been extremely supportive as have all of my owners."
Dunlop enjoyed a high-profile winner at Ascot on Saturday with Adaay In Asia, who also struck gold at Goodwood, landing the Dubai Duty Free Shergar Cup Sprint.