Avesu: Located in Germany, they offer a wide range of hiking shoes. See: https://www.avesuveganshoes.com/vegan-mens-shoes/hiking-outdoor-com.html
Ethical Wares: Located in the United Kingdom, they offer several hiking/walking boots. See: https://www.ethicalwares.com/footwear/walking-boots-and-shoes/
REI: Search under vegan and you’ll find several vegan hiking boots. See: https://www.rei.com/c/hiking-boots/f/f-vegan
Treksta: Located in the USA. Choose their vegan options. See: https://www.trekstausa.com/vegan_styles
Vegetarian Shoes: Located in the United Kingdom, they offer several hiking boots. See: https://www.vegetarian-shoes.co.uk/search.html?searchterm=hiking%20boots