The Adventurer (Original title Mikael Karvajalka) by Mika Waltari is a fictional tale of young Finnish man, Mikael Karvajalka, set in medieval Europe. Many of the larger events in the book are actual events, but Mikael's involvement in them is ficticious. The book starts in the city of Turku and follows Mikael along an adventure througout Europe.

The first half of the book is of Mikael Karvajalka's tale and the second half is The Wanderer (original title Mikael Hakim), by the same author.