Princess Marie, wife of reigning Prince of Liechtenstein Hans-Adam II, died on Saturday at the age of 81 after suffering a stroke earlier this week, the Princely House said in a statement.
Princess Marie suffered a stroke on Wednesday and died in hospital on Saturday afternoon.
Her family had gathered around her, and after receiving the last rites, she "passed away peacefully and with great trust in God," the statement said.
The princess consort, like her husband, had largely withdrawn from public life in Liechtenstein, a small principality between Austria and Switzerland with nearly 40,000 inhabitants.
Prince Hans-Adam II, who took the regency in 1989, entrusted the management of the principality's affairs to his eldest son, Prince Alois, in 2004.