Olsen sits next to 4 phonetic neighbors — Nelson, Olson, and Elson are the closest matches by sound. Most share Olsen's Old Norse-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of Ole (ancestor)"
"warrior, strong one"
"born from the ocean, son of the sea"
"God is gracious (via Shawn/Sean/John)"
"whole, healthy"
"strength, powerful one"
"of love"
"phonetic rendering of initials J and C"
"cold, enduring"
"highlands, uplands"
"modern invented name with noble, airy connotations"
"may God protect"
"blessed"
"Wise one, a sage person"
"great happiness"
"royal settlement, king's town"
"concluding musical passage"
"hare meadow"
"white, fair-complexioned"
"son of Hays, hedged area"
"fire, energy (sound symbolic)"
Similar sound: These names share phonetic patterns with Olsen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Olsen.
Rhythm: Olsen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.