I know I can find population totals for incorporated places here, but I'm unsure where to find a similar list for census designated places. This Wiki table seems to indicate this data is out there somewhere, but after scouring the census.gov website, I've not come up with anything. Anyone have any ideas?
These data are available from the 2010 Census or the 2014-2018 American Community Survey (ACS) 5-year estimates. (1 year data are only for places with 60,000 population or more, so you need to use the 5-year data or go back to 2010 Census)
Probably the easiest way is to check out NHGIS to get table B01003 for all places in the U.S. in a shapefile (point) https://www.nhgis.org/ Once you have that, you can filter on the LSAD field = 57 to get just the CDPs.
If you don't have a way to read a shapefile, though, this may not work out for you. So you can get the data from data.census.gov:
If you want entire US it will be a large file. You can get the data from https://data.census.gov/ by searching for table B01003 (just put the table in the search box). Table B01003 is the population estimate. Then be sure to change the Product to "2018 ACS 5-Year Estimate Detailed Tables".
then go to "customize table" and select the geographies you want. You can get all places in US or do it by state.
Here is a link to all places in Alabama: https://data.census.gov/cedsci/table?q=b01003&g=0400000US01.160000&tid=ACSDT5Y2018.B01003&hidePreview=true&moe=false
here is a link to all places in US but it is so big it may take awhile to come up and my Internet connection kept timing out: https://data.census.gov/cedsci/table?q=b01003&g=0100000US.160000&tid=ACSDT5Y2018.B01003&hidePreview=true&moe=false
You will need to then filter out to get just the CDPs.
Use arcgisonline.com you will find most updated and prepared data also its free nowadays(Corona_virus free accounts subscription to learn staying in home)
also if you are having trouble in preparing such a huge data like you have an excel from source like wiki that contains name of county and population of county you can geo-code that names to get point (X-Y Coordinates) that cane be mapped easily.
see this too
(I do geocode by awesome table https://encrypted-vtbn1.gstatic.com/video?q=tbn:ANd9GcRVWxGbnhbTpJfVROAvZwZ6eAL31tUA2H8f1930Wfdut8vbHUeO)
For future readers, this is how you can directly download table B01003 from the census website if it's too large to open in the browser:
Visit the advanced search https://data.census.gov/cedsci/advanced
Select Geography>Place>All Places in United States
Click Search in the lower right Click Tables in the upper left
Notice the first table result is DP05 and is too large to display on screen. This is good because it does not freeze the site. Notice the second table result is B01003. Download the table following the method on page 2 at https://www2.census.gov/data/api-documentation/how-to-download-a-table-as-a-csv-file.pdf During the download process, when you click B01003, be careful to only click the checkbox to download it. If you click the table area outside of the check box, it will try to display the table in the preview and freeze the site