G'day!  
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Do you mean a place where pro web designers can connect, ask Qs, get As, share ideas, etc.?
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Or do you mean that you are looking for a web designer to do some work for you?  
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I'll go with the latter and assume that you are looking for someone to help you with design of a website for you. I don't know of a comprehensive resource, but I'd start by looking at websites of Providers, pick the ones you like, and look for info in the fine print at the bottom of the page: "Designed by ..." or "Designed using [do it yourself website, such as Wix]"  
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If you can't find the designer's info, contact the Provider directly (email; twitter DM, TER PM, ...) and ask her for the info.  Some Providers design and maintain their own sites; it wouldn't surprise me if someone stepped up to offer their services.