The main ceremony was held at Ljubljana's Cankarjev dom on Monday evening with parliamentary Speaker Milan Brglez as the keynote speaker. He stressed that the whole of Europe and in particular the EU needed new "Luthers" today to hold up a mirror to us and remind us of our roots.
Remembering the reformation, Brglez said these roots are respect for "law, human rights, including minority rights, and the dignity of all".
Reformation Day marks the day in 1517 when German priest Martin Luther nailed his Ninety-five Theses on the door of the All Saints' Church in Wittenberg, which sparked the Protestant Reformation.
The movement had a profound impact on the religious and other aspects of life in Europe, as Luther promoted the use of national languages in religious teachings instead of Latin.
According to cultural and literary historian Jonatan Vinkler, the more than 50 titles of books produced by Slovenians in the period show that Slovenian Protestants wanted to convey the word of God to ordinary people in the widest possible extent.
The Reformation movement in Slovenia was epitomised by Primož Trubar (1508-1586), a Protestant priest who wrote the "Abecedarium" spelling-book and "Catechism", the first books in the Slovenian language.
Apart from Trubar's work, notable achievements were also Jurij Dalmatin's translation of the Bible and a linguistic manual by Adam Bohorič, which set the writing standard for the next 200 years.
Although a predominantly Catholic country, Slovenia has been celebrating Reformation Day as a national holiday since 1992 and the government declared this year the Reformation Year. Several events marking the 500th anniversary have been held around the country.