Ryanair will bar British nationals from acquiring new shares in the company and will strip current UK investors of several rights in the event of a hard Brexit.
The Irish airline said that it is putting plans in place to protect itself from a no-deal Brexit and ensure it will remain majority EU-owned and controlled.
All Ryanair shares held by non-EU shareholders, including British ones after Brexit, will be treated as "restricted shares", meaning that they will have no entitlement to attend, speak or vote at any company meeting.
Furthermore, Ryanair added that the prohibition on non-EU nationals to acquire shares will mean Brits will be barred from buying shares in the firm.
"Consequently, with effect from hard Brexit day, UK nationals will not be permitted to acquire ordinary shares in the company," the firm said.
EU regulations stipulate that airlines must be more than 50% controlled by investors from the bloc to fly freely across the continent.
The company said the resolutions have been passed by the board and they will come into effect on the day that UK nationals no longer qualify as EU residents.
As it stands, Britain is legally on course to crash out of the EU without a deal on March 29.
Ryanair boss Michael O'Leary has been vocal about his fears over a hard Brexit.
Last month IAG, the owner of British Airways, Aer Lingus and Vueling, also placed a limit on non-EU shareholders.