Hi, I have a 2011 Ford Escape XLT V6 3.0L
I recently bought this car from someone else the driver side door is leaking and for the life of me I can't find the OEM part number for the weatherstripping.

Attached are pics and circled in white.

 

A good place to start with something like this is to take a dollar bill, close the door with the dollar bill jammed between the weatherstrip and the door. If you can pull the bill out that is where the water is getting in. Now, depending on where, and how loose it is, will determine what you might try next.
Sometimes all it requires is a slight adjustment of the door striker post, moving it in maybe a 1/16 in and that may be all that is required to bring the door in enough to provide a good seal between the door and the weatherstrip. Then retest it again with the dollar bill. Most of the time that will take care of the leak. We don't want to get too zealous with this adjustment because it can make the door harder to close and open. Go slow and easy.

I should have inquired if the vehicle had any damage to require door repairs.

 

I'm not entirely sure if there is/was damage to the door. I recently purchased this car second hand. I like the engine and the way the car drives, but I keep getting these "pleasant" surprises about the car. Like, green slime in a dry rotted tire, front brakes that seized 3 days after I bought the car (had to replace the brake line, calipers and rotors on both sides), my mechanic saying the car was in an accident (yaaay more surprises!), and sopping wet floor whenever it rains.
It sucks because I found driving the escape really fun.
Thanks for the help, I'll try the dollar bill test and adjusting the striker/looking for damage.