'Bayou Billionaires' Star -- Blows Wad on Hairpiece

George Washington had one ... so did Frank Sinatra ... and now TMZ has learned the bald rich guy from "Bayou Billionaires" is also sporting a brand new skull rug.

It's just the latest purchase in a tidal wave of spending ... ever since Gerald Dowden and his family became overnight rich folk when a drilling company asked to drop four natural gas wells on their Louisiana property.

Family members tell us ... the wig purchase was a product of peer pressure from Gerald's kids ... who thought he'd look better with some fur on his melon.

TMZ spoke to Gerald’s wife Kitten Dowden who says she's NOT a fan of the new fake 'do ... telling us, "He wore it out to eat the other night at our favorite steakhouse and the waiter who always serves us thought I was there with another man!"