Modern invented surname-style name, likely influenced by Norse -by place names meaning farm or settlement.
Krosby is an Anglicized and modernized variant of Crosby, an English and Scandinavian surname with Norse roots. The original *Crossby* or *Crosby* derives from Old Norse *kross* (cross) and *byr* (farmstead or settlement) — literally a settlement near a cross, likely a stone wayside cross of the kind erected throughout the Viking-influenced areas of northern England and the British Isles during the early Christian period. There are several places called Crosby in Lancashire, Cumbria, Merseyside, and North Yorkshire, all bearing this quiet Norse-Christian heritage.
The name's most famous bearer is Bing Crosby (born Harry Lillis Crosby), the mid-20th century American entertainer whose velvet baritone defined popular music from the 1930s through the 1950s. Bing Crosby was at one point the best-selling recording artist in the world, and his warm, unhurried style made the name Crosby synonymous with a particular kind of effortless American cool. The surname has been used occasionally as a given name in his wake, and Krosby takes that tradition and refreshes the spelling for the contemporary taste for K-initial names.
As a given name, Krosby belongs to the thriving genre of Scandinavian-inflected surname-names — think Rigby, Colby, Bransby, Kirkby — that feel both rooted in English landscape history and pleasingly modern. The K spelling sharpens its visual distinctiveness. It is most often chosen by parents who want a name that sounds established but looks fresh: a name that could belong to a Viking, a jazz singer, or a child starting kindergarten today.