In general, a legal owner is someone recognized as having legal title to a piece of property. There can be multiple legal owners to a particular piece of property in what is known as a joint ownership.
There are a variety of ways someone can become the legal owner of a piece of property, such as through purchase, capture, patent, finding (see lost property), adverse possession, etc.
Sometimes, the term legal owner describes a person who holds legal title to property for someone else's benefit. See, e.g., Trustee and Record owner.
[Last updated in June of 2023 by the Wex Definitions Team]