Yes, leather shoes can be worn for both casual and formal occasions, making them quite versatile. The versatility of leather shoes largely depends on their style, design, and color. Here are a few examples:

1. Oxford Shoes: These are classic formal shoes with closed lacing. They are typically made of polished leather and are suitable for formal events like business meetings, weddings, or black-tie events.
2. Brogues: Brogues are a type of leather shoe with decorative perforations or patterns. They come in various styles, including wingtips, quarter brogues, and longwing brogues. While the more traditional and polished brogues are suitable for formal occasions, slightly less formal variations can be worn for smart-casual or semi-formal events.