Josilin is of Hebrew origin, meaning "God shall add." It is a unisex name but more commonly used for females. The name Josilin is a variant spelling of Josephine and Joselin. In the United States, its usage peaked in the late 19th century, with only occasional appearances since then. Notable individuals named Josilin include American actress Josie Bissett and French singer Josiane Balasko.
The name Josilin experienced a peak in popularity between 2001 and 2003 with 6 births each year, followed by another spike in 2005 with 11 births. Overall, there were 58 babies named Josilin born over this period.