Mermaid of Zennor is a popular Cornish folk tale.
Long ago, a beautiful and richly dressed woman occasionally attended services at St. Senara's Church in Zennor, and sometimes at Morvah. The parishioners were enchanted by her beauty and her voice, for her singing was sweeter than all the rest. She appeared infrequently for scores of years, but never seemed to age, and nobody knew whence she came, although they watched her from the summit of Tregarthen Hill. After many years, the mysterious woman became interested in a young man named Mathey Trewella, "the best singer in the parish." One day he followed her home, and disappeared; neither was ever seen again in Zennor Church.
The villagers wondered what had become of the two, until one Sunday a ship cast anchor about a mile from Pendour Cove. Soon after, a mermaid appeared, and asked that the anchor be raised, as one of its flukes was resting on her door, and she was unable to reach her children. The sailors obliged, and quickly set sail, believing the mermaid to be an ill omen. But when the villagers heard of this, they concluded that the mermaid was the same lady who had long visited their church, and that she had enticed Mathey Trewella to come and live with her.
The parishioners at St. Senara's commemorated the story by having one end of a bench carved in the shape of a mermaid. A shorter account of the legend was related to Bottrell on a subsequent visit to Cornwall. The mermaid had come to church every Sunday to hear the choir sing, and her own voice was so sweet that she enticed Mathey Trewella, son of the churchwarden, to come away with her; neither was seen again on dry land. The famed "mermaid chair" was the same bench on which the mermaid had sat and sung, opposite Trewella in the singing loft.
- The story of Mermaid of Zennor was merged with that of Saint Senara in a movie The Mermaid Chair.