Sweden (which included Finland at that time) had a literacy rate of over 90% in the late 18th century. The ability to read was required of the entire population since the Church Law of 1686, and each parish had a comminister whose responsibility it was to teach and test people, and people were tested in annual catecheticals called 'home examinations' (husförhör).

This definition of literacy is not really the modern one though, because the reading consisted mainly of known texts that people had likely memorized large parts of - mainly Luther's Small Catechism. People were less proficient at reading unknown texts, and even fewer people, women in particular, could write. Nevertheless, it seems likely it was the highest rate in the world prior to the rise of mandatory public schooling in the 19th century.