Where to park my car near National Mall on Saturday?

Can you clarify what show? The National Mall is a large park extending from the US Capitol to the Lincoln Memorial. They have festivals and events there, but no "shows". Might you be thinking of National Harbor, which is in Maryland? Or as has been mentioned, the National Theater in Downtown DC? If you say what show, we can be of more help to you.

Don't drive in to DC park your car out at Wolf Trap VA and ride the (Metro) into town Go (on line) and find the best location depending on where you live Good Luck

Perhaps if you mentioned what "show" you were going to see, you could get better options than what has already been offered. They are all good options, but if you had more detail in your question, perhaps you could get the best advice for you. I say this because nearly every even in DC, especially near the mall or national theater, usually list parking options for that event. They do this precisely for folks like yourself. BTW, free parking in DC proper on a weekend is pretty much fantasy.

Many of the streets along the National Mall have parking, although with a three hour limit as others have said. Of course there won't be too many office workers in town on a Saturday, so finding street parking will be easier than during the week, but there are likely to be other tourists. Also, as others have said, the National Mall is quite big (and you can't drive ON the actual mall), and I'm not sure exactly where the show is that you're seeing so I can't say which street is the best to try and find parking - chances are you'll have to have to walk at least a couple blocks no matter what though. Many garages have much cheaper rates on weekends though, so you'll probably be able to park in a garage for around $10 for the day, which might be easier than driving around looking for street parking. Also, parking at one of the outer Metro stations might also be an easier option - most outer stations have garages or parking lots and it's not too expensive.

The National Mall is a couple of miles long, with several Smithsonian buildings along it, so you are going to need better directions. Make sure they did not mean the National Theater, which is several blocks away from the National Mall. The National Mall itself has free parking. It has a three hour limit. It is often completely filled up. Nearby streets have meter parking even on weekends, and the meters are expensive. You might be able to find parking in parking garages located under office buildings in the vicinity. Make sure their closing hours are after your show is over. If you want free parking, your best bet might be to park at a garage at a Metrorail station (which is free on weekends) and take Metrorail to your destination.