- Heritage Foundation: 25
 - American Enterprise Institute (AEI): 11
 - Hudson Institute: 4
 - Competitive Enterprise Institute (CEI): 3
 - Hoover Institution: 3
 - Center for Strategic and International Studies (CSIS): 3
 - Bipartisan Policy Center (BPC): 3
 - Brookings Institution: 2
 - Manhattan Institute: 2
 - Cato Institute: 1
 - R Street Institute: 1
 - Carnegie Endowment for International Peace: 1
 - Center for Strategic and Budgetary Assessments (CSBA): 1
 
Think Tank Watch keeps its own internal list which shows that there are even more think tankers than the ones listed who have helped the Trump team. ["Only" around 60 people total have come from more well-known, "traditional" think tanks, based on our analysis of ProPublica's count.]
In January, the Heritage Foundation said that approximately 70 of its former employees have worked for the Trump transition team or as part of the administration.
Here is a previous Think Tank Watch piece about the influence of the Heritage Foundation on President Trump, whose administration has adopted 64 percent of the think tank's recommended agenda.