The Book of Judges does not provide any explicit information about its author, and the internal evidence suggests that the author lived after the period of the judges.
Traditionally, some Jewish scholars have attributed the book to the prophet Samuel.
However, there are some challenges to this theory. The book seems to reference events that happened after Samuel's lifetime. So, most scholars believe the book was compiled and edited long after Samuel's time.
"Authorship and Date of Composition
THE
BOOK OF JUDGES is anonymous. It is apparent that the book is a
collection of various blocks of material concerning the different
judges. Some of the stories may have existed very early in oral or
written form, but none of these blocks are attributed to any particular
source in the text. Modern scholars have expended great amounts of time
and energy in an attempt to identify these sources, but with limited
success.10
The
reference in 18:30 to “the time of the captivity of the land” seems to
refer to the Exile (either 722 or 586 B.C.) and suggests that the final
edition of the book came from the Exile or afterwards.11 Thus the
precise author and date are uncertain. But this should hardly deter the
reader from understanding the book’s message."
[NIV Application
Commentary Series. Judges, Ruth]