Le Droit Humain Belgium was founded in 1911 with the help of a lodge of the Grand Orient (an irregular men-only lodge). After that LDH grew towards being the second largest Masonic order in Belgium with 61 lodges and 6.500 members;
Lithos Confederatie van Loges (L.C.L.), was founded in 2006 and already has 33 lodges in Belgium (most of them), Germany and Switzerland. There are about 1200 members. Lithos lodges can be both mixed, men-only and female only;
(Member of Clipsas)
Grand Orient of Luxembourg. An order with male and mixed lodges which was re-founded in 1982. It has 3 lodges in Belgium (Gent, Luik and Turnhout);
International Order of the Ancient and Primitive Rite of Memphis-Misraïm is active in Belgium. I know this order has men-only and mixed lodges, but I have not been able to find out if the Belgian Grand Lodge admits women, how many lodges they have, where they are located and it this is a system starting with the ‘blue grades’ or are only meant for Master Masons.
I would like to invite Dutch and Belgian visiters to visit the Dutch version of this website. It has (much) more information and a Google map to find a lodge nearby.