Walter Sans Avoir (in French Fr.

Gautier Sans-Avoir) (died 1096), also mistakenly known as the Penniless, is the lord of Boissy-sans-Avoir in the Île-de-France.

As lieutenant to Peter the Hermit he co-leads the People's Crusade at the beginning of the First Crusade.

Leaving well before the main army of knights and their followers, Walter leads his band through the Holy Roman Empire, the Kingdom of Hungary and the Bulgarian province of the Eastern Roman Empire, traveling separately from Peter.

While they pass through Germany and Hungary uneventfully, Walter's followers plunder the Belgrade area, drawing reprisals upon themselves.

From here they continue to Constantinople under Byzantine escort.