Sure. I have done 2 in a 15 gallon Smart Pot type container several times with no problems and excellent production assuming you maintain adequate feeding and watering.

Dave

I agree with Dave.
Additionally, depending on the shape of the container you can plant up to 4 eggplants in 25 gal. soil. Say you have a planter, 12" wide, 12'' deep and 4 feet long, you could plant 4 eggplants in it. That is equivalent of one plant per square foot.

These are my new gigantic round plastic pots. I want to put eggplants in some. I was going to plant all the tomatoes in raised beds, but I might try a few in these pots.
I haven't read up on the feeding yet, was planning on weekly diluted dissolved fertilizer or maybe some Osmocote.
I do plan to be good about the watering too. I designed the vegetable area this year with a fence around it but there is still a bit of room for the dogs outside the fence. That means they can be out there playing while I'm watering.
Because the area is compact I plan to hand water with a hose. I do have a sprinkler and I've used weeper hoses in the past, (and have one in a side flower garden) but since I am gardening more intensively in a smaller area I'm thinking I want to look at and water every plant so I can catch any adverse issues like bugs before they get out of hand.
Thanks for the answers.

was planning on weekly diluted 1/2 strength dissolved fertilizer AND some Osmocote works well in containers.

Dave

'dissolved fertilizer'
What brand do you use?

You think maybe I can fit 3 in each container?

Depends on what kind of eggplants you are growing. I've grown four Japanese types (ichiban, pingtung long and hansel) or three Italian types (rosa Bianca and listada de gandia) in 25-gallon pots, and thought they produced well. The plants are all smaller than common eggplants like Black Beauty.

They are Japanese type, called Millionnaire.

I actually prefer to grow eggplants in pots. There are fewer (but not none) flea beetles that way. They produce extremely well. Digdirt is right about the fertilizer. Half strength miracle grow (or other liquid fertilizer) weekly and osmocote once a month. I use the same regimen on pepper plants in pots too.

Thank you for your answer. I kind of had the notion I'd try out some square foot gardening this year so there are two small raised beds which will be mostly just peppers, so no peppers in pots this year.