The plug for my rear left wheel speed sensor is broken. Where can I get a replacement?

 

I don't see any info on your vehicle here or in your profile, so...

Call the dealer for the part number and price.
Then Google the part number to see where it's available for a lower price.

 

2011 JKU.

All the JKs should share the same plug for that sorry.

 

They should, but you never know until you look it up. My parts books only go to 2011.

Speed sensor, rear 52125003AB

It brings up all kinds of sources.
You can even try your local auto parts store.
My local Car Quest has them for $19.50
Advance Auto has it for $16.99