William Henry West Betty (13 September 1791 in Shrewsbury – 24 August 1874 in London) was a popular child actor of the nineteenth century, known as "the young Roscius".
Both of William's parents were very wealthy due to inheritance. His mother inherited money from Shropshire and his father inherited money from the north of Ireland. According to legend, Betty’s father frivolously spent his money on anything, which resulted in his losing a large portion of his inheritance. This loss might have contributed to the extreme exploitation of his child prodigy, William.
William Betty first showed his desire for the stage at the age of eleven when, in 1802, his father took the young boy to Belfast to watch Sheridan’s Pizarro, starring Sarah Siddons in the role of Elvira. Her performance inspired him so much that William stated, "I shall certainly die if I may not be a player." Betty’s father introduced William to Michael Atkins, manager of the Belfast Theatre. After meeting the child, Atkins said, "I never dared to indulge in the hope of seeing another Garrick, but I have seen an Infant Garrick in Betty."
Not long after meeting Atkins, Betty was introduced to the theatrical prompter Thomas Hough, so he could direct, train, and mentor young William in the role of Osman in Voltaire’s Zair. While this was going on, there was an insurrection in Ireland which resulted in the closing of the Belfast theatre. Atkins knew he needed a huge attraction to bring in the crowds and he immediately thought of William. After some hard planning, it was settled, and on 11 August 1803, the eleven-year-old William Henry West Betty debuted professionally as the well-known Osman. His appearance brought in a large crowd, and reports stated that his performance was flawless and extremely well received.
He next took on the role of Young Norval in John Home's Douglas. This role fit him much better since he was actually playing a child and, once again, he astonished people in the theatre. News of Master Betty soon began spreading across Europe.
Master Betty’s fame extended beyond just Belfast to Dublin, where Betty’s father talked to Frederick Edward Jones, manager of the Crow Street Theatre. They were able to reach an agreement for Betty to appear again in Home's Douglas at the Theatre Royal, where he debuted on 28 November 1803. There he also played Frederick in Elizabeth Inchbald's Lovers' Vows, the title role in Tancred , and in William Shakespeare's Hamlet. It was said that in three hours of study he committed the part of Hamlet to memory. The citizens of Dublin became so excited over Betty that the civil authorities extended the curfew an hour for those attending the theatre.