The pub giant, which operates around 800 sites, did not give a reason for the sale.
JD Wetherspoon boss Sir Tim Martin has sold around £10m worth of shares in the pub chain.
Martin, who is also chairman of the group, founded the pub giant in London in 1979.
He sold 1.361m shares in the company at a price of £7.39 per share on 26 July, according to an announcement on the London Stock Exchange this morning.
Shares in Wetherspoon dropped 0.6% to 745p on Monday following the announcement.
The sale has reduced his stake to 24.58%, or 30,382,253 shares, in the company.
Wetherspoon, which operates around 800 UK pubs, did not disclose the reason for the sale.
Earlier this month, Wetherspoon said like-for-like sales across its sites had risen 5.8% in the 10 weeks to 7 July.
The company boasted staff retention was at its “highest ever level” as over 11,000 people had worked for the group for five years or more.
Martin also hit back after a trade union boss accused Wetherspoon of being a "crappy" employer and said the pub chain had paid over £504m in free shares and bonuses to staff since 2007.
Despite its sales boost, Wetherspoon has faced a major hike in costs, with its wage bill rising £164m and energy costs increasing by £28m in the current financial year.
However, the group is continuing to expand and will open a £2.5m pub at London Waterloo Station this summer.
It will be the second multimillion-pound Wetherspoon pub to open at a major London station this year, after the chain launched a £2.3m Captain Flinders pub near Euston in January.