Can I patent a clothing line design? Can I patent a fashion design?

Yes, but they are rare!  Why?

The US Patent Office will grant a Design Patent to anyone who invents a new, original, and ornamental design for an article of manufacture, such as an article of clothing or shoes. However:

1) Its expensive to patent every design in your portfolio. Typically, each Design Patents cost around $1200-1500 to file the application and depending on the challenges raised by the patent office additional costs arise to argue the issuance of your design patent, and all patents require maintenance fees to maintain the patent protection once granted.  Therefore it is expensive to patent each design your entire clothing line design or portfolio.

2) Design patents take time to issue. Design patents averages 12-18 months to navigate the US Patent Office and if successfully filed and prosecuted you will have ownership of the design for 14 years.  Fashion design trends move much quicker than the design patent time frame making it hard to predict and protect such fashion trends with a design patent.

Since it is difficult to protect a fashion design under patent, alternatively some protection for a clothing line design is found under copyright and trademark. For, example, designer names protected under trademark have brand value.