The present invention provides a bag system with adjustable flexible straps. The bag system with adjustable flexible straps includes: a bag and one or more adjustable stretch strap systems. The bag may be a backpack, a handbag, a purse, a duffle bag, or a piece of luggage. The present invention also provides an adjustable stretch strap system. The adjustable stretch strap system includes: a flexible elongated member, one or more first members, and two or more second members; and one or more hooks for coupling to the flexible elongated member.