Since we have no idea where you live or what the situation looks like (room to plant, etc.) I'd suggest a fence. If you can come back with photos or better descriptions and a geographic location, suggestions may get a bit more meaningful :-)

And what do you mean by "tall"??

You are still not providing us with adequate visuals :-) We need a picture......something that shows where the privacy is required and at what height. And where you are located. Plants that grow well in southern California (or Florida) are unlikely to do well in Missouri. Or even Texas.

Now ewe see your patio still not the pool.

I would need a privacy fence around a pool with neighbors so close.

If it were me, I'd plant a mix of large shrubs (10-12 ft tall and wide), small trees, some conifers, and one or two large trees for down the road size and interest. I'd plan for spring bloom, fall berries and color. But maybe you just want a wall of evergreen.

Is the fence the boundary? And you put the pool right next to it? Do your neighbors a favor and plant the DENSEST screen of staggered evergreen shrubs and trees you can. It will not be a noise screen (only a solid barrier can do that) but it will muffle it somewhat and be psychologically ameliorating. People with pools have no idea how dreadful it is to be their neighbors. Even quiet conversations are amplified by the water over long distances. The sound of (happy!) children splashing and squealing is... well, I'll stop. Just be aware.

I agree, kita. There is a beautiful home I’d like to buy, but it’s across the street from an inground pool owned by Party Animals old enough to know better. I’ll have to pass. And feel sorry for the neighbors.

Plant arborvitae. Lots of them.