Willas Tyrell is the eldest son of Mace Tyrell and Alerie Tyrell. He has two younger brothers, Garlan and Loras; and one sister, Margaery. Just like his siblings, Willas is the grandson of Olenna Tyrell - nee Redwyne.

As the eldest Tyrell son, Willas is heir to Highgarden and the lands and titles of House Tyrell. Willas is unmarried, despite being a valuable marriage prospect as heir of the Reach, because the Tyrells are holding out for the best possible match to forge a marriage alliance.

The men of House Tyrell in the current generation tend to be well-meaning but not very intelligent, yet Willas is considered an exception to this. Willas is often noted as a studious, well-educated, and kind, and is renowned for breeding the finest hawks, hounds, and horses in the Seven Kingdoms.

In contrast to his father and siblings, he does not take an active part in the plotline. He suffered a crippling injury to his leg in his adolescent years from a tournament accident, while he was facing Oberyn Martell in a joust; according to Oberyn, as Willas fell from the saddle, his foot got caught in his stirrup, dragging his horse down on top of him.

Though this has increased the animosity between the Tyrells and the Martells (who had been bitter enemies for many generations prior to the incident), Willas himself is relatively calm about the injury and does not blame Oberyn, acknowledging that it was an accident and not his fault, and even befriending Oberyn to an extent. Willas even sent a friendly letter by raven, to Oberyn Martell, about their shared interest in breeding horses.

Willas Tyrell is a human a part of the House and highborn noble family of Tyrell, and you have held titles of being a Lord of Highgarden, in the Reach which is one of the Seven Kingdoms of Westeros.

Willas Tyrell's brothers Garlan and Loras also have this title, being the same male gender as him. Like them too but considered first as the first born child to Mace and Alerie Tyrell, he is the heir to Highgarden, heir to ruling the Reach after his grandmother Olenna and father Mace.

Physically, Willas Tyrell is 6 feet 3 in height. Willas has an athletically toned, muscular body build with a broad chest and shoulders. Willas has fair-toned skin that is slightly pale. Willas has shoulder length curly brown hair that also falls a little bit on his forehead. Willas has a sharply defined jawline. Willas has slight facial hair of a mustache and stubble on his chin and the bottom half of his cheeks. Willas Tyrell has blue eyes.