Where does “Jonasson” come from?

Jonasson (Swedish) comes from Swedish Jonas, from Swedish son, from Old Swedish son, from Old Norse sonr, from Proto-Germanic sunuz, from Proto-Indo-European *suhnús.

Ancestry of “Jonasson”, step by step

Jonasson traces back through 3 separate lines of ancestry.

via Swedish Jonas

Step	Language	Word	Meaning
1	Swedish	Jonas	Jonah
2	Swedish	son	son; someone's male child
3	Old Swedish	son	son
4	Old Norse	sonr	son
5	Proto-Germanic	sunuz	son
6	Proto-Indo-European	*suhnús	—

via Norwegian Bokmål Jonas

Step	Language	Word	Meaning
1	Norwegian Bokmål	Jonas	Jonah, the Old Testament prophet and the biblical book named after him
2	Latin	Iōnās	Jonah Old Testament prophet
3	Ancient Greek	Ἰωνᾶς	Jonah, a given name, famously held by the Old Testament prophet to Nineveh, swallowed by a large fish. Also, the father of Jesus' disciples Peter and Andrew
4	Hebrew	יונה	dove, pigeon; dove
5	Hebrew	יוֹנָה	dove

via Icelandic Jónas

Step	Language	Word	Meaning
1	Icelandic	Jónas	—

Every word from Proto-Indo-European *suhnús →Every word from Proto-Germanic sunuz →Every word from Old Norse sonr →

Jonasson — Etymology, Origin & Word History | Etymology Explorer