Rawganique was started on Denman Island in Canada. They are one of the few strictly sustainable lines manufacturers of formal wear for men. Their Eco Couture Collection has a good range of ethical suits, jackets, slacks, shirts and accessories for the eco-conscious wedding goer. Rawganique also has a great wedding registry!
If you’re looking for men’s formal separates, Downbound has some blazers and slacks to choose from. For affordable classic organic cotton oxfords, try Boll Organic and Greenloop. Always remember too, that the most eco-conscious choice for men’s formalwear is probably vintage.