|Nationality||The Southern Isles|
|First appearance||Frozen: The Kingdom of the Sun|
Jakob stands out as the most kind and innocent of the Westergaard royal family, completely untouched by the cynicism and egotism his twelve brothers exhibit. He expresses a childlike delight over the simplest pleasures, and is relentlessly optimistic, even in the face of disasters. However, Jakob's optimism can quickly turn to ditziness when he misinterprets situations as more positively than they really are.
Unfortunately, there is a tragic element to Jakob's virtue: He suffers from a mental handicap, implied to be from experiencing head trauma as a baby at the overeager hands of his youngest older brothers, Theodor and Thomas. This disability is the root of Jakob's recurring gullibility, an inability to register facts on his own, and being easily influenced by what others tell him. His artless nature makes it difficult for Jakob to hold down a position within the Southern Isles' government like the rest of the Westergaards, and thus he mostly acts as an attendant for his older brothers.
Jakob is a young man with a lean physique, fair freckly skin, brown eyes, and messy shoulder-length Titian or orangey-blond hair.
- Jakob is the only one of Hans' brothers who never bullied or intentionally caused him pain.
- Hans claims that Jakob once came close to killing himself by trying to open a jar.