Duncan MacMillan

Duncan MacMillan (born 1937) is a U.S.-based billionaire in the finance industry, associated with New Jersey, with an estimated net worth of ~$1.8B. Federal election records show political contributions from 2019-03-28 to 2025-12-05 totaling $15,310. Foundation filings linked to the Macmillan name show combined assets of $111,127,775 and $0 in grants paid in the most recent reported tax years. RTB FEC ProPublica 990

Philanthropy

ProPublica-reported 990 data lists three foundations: the Katherine Wells Macmillan Foundation (MN) reported $110,762,761 in total assets in tax year 2023, $41,837,081 in total revenue, $4,928,838 in total expenses, and $0 grants paid. The Donald A Macmillan Foundation (TX) reported $365,014 in assets in tax year 2023, $21,195 in revenue, $7,317 in expenses, and $0 grants paid. Across the listed foundations, total assets were $111,127,775 and total grants paid were $0. ProPublica 990

Political Activity

FEC data shows 100 contributions totaling $15,310 between 2019-03-28 and 2025-12-05, with $12,425 attributed to Democratic recipients and $2,885 categorized as Unknown (primarily through ActBlue). The top recipients by amount were Friends of Schumer ($5,800), Mikie Sherrill for Congress ($2,900), Josh Gottheimer for Congress ($2,900), ActBlue ($2,885), and Biden for President ($425). The recorded giving is concentrated on Democratic-aligned committees and candidates. FEC