Penley began his stage career in 1871 in farce and was soon performing in musical theatre. From 1875, he appeared in several runs of Trial by Jury, making an impression when he became a replacement in the role of the Foreman of the Jury.
A young Penley began his acting career in 1871 in comedic roles and quickly transitioned to performing on stage in musical shows. By 1875, he had secured leading roles in several productions of Trial by Jury, earning recognition when he stepped into the Foreman position.