William MacMillan
Profile Summary
William MacMillan is a U.S. billionaire based in Colorado, born in 1954, associated with the diversified industry. His estimated net worth is ~$1.7 billion RTB.
Philanthropy
The Macmillan Family Foundation Inc., based in New York, reported $473.6 million in assets, $82.6 million in revenue, and $30.4 million in expenses for tax year 2023. The foundation reported paying $24.7 million in grants that year ProPublica 990.
Political Activity
FEC records show at least 100 federal contributions in the most recent 100 contributions on file, covering only a sampled period from August 22, 2017, to May 1, 2026. Those sampled contributions totaled $19,739.64: $13,011.30 to recipients with unknown party designation, $6,325 to Republican recipients, and $403.34 to Democratic recipients FEC. The largest listed recipients in the sample were Donald J. Trump for President, Inc. ($5,650), Trump Victory ($5,400), and the Association of American Physicians and Surgeons PAC ($3,000) FEC.
These donations are matched to this person by name only, so some may belong to a different person with the same name: FEC filings can include a donor's employer and city, but our matching does not check them against what we know about this person.
U.S. Presence
Philanthropy
Foundations are matched to a person by name, not by trustee records — so a same-surname family foundation can land here in error. Every entity below links to its full IRS filing; if one doesn’t belong, tell us at hello@skylarkcreations.com and we’ll pull it.
Political Contributions
These figures cover the 100 most recent of 132 federal contributions on file, not the full record. The total, party split, top recipients and dates below are all computed over that sample, so each is a floor rather than a complete figure.
By Party (in the sample)
Every party in this sample is listed here. The bars are rounded for display; unrounded they total exactly $19,739.64.
Top Recipients (in the sample)
Matched by name only. These donations are matched to this person by name only, so some may belong to a different person with the same name: FEC filings can include a donor's employer and city, but our matching does not check them against what we know about this person.
Score Breakdown
The giving score is a weighted average of 2 components. The formula is open and versioned — the weight percentages below show how much each component contributes to the final score.
Evidenced charitable giving — built on what they actually give each year, not parked assets. Dominated by generosity (annual giving relative to net worth — the share of your fortune you give), plus the absolute scale of that giving, plus a small nudge for signing the Giving Pledge (a commitment, not a realized action).
Data: ProPublica 990 charitable disbursements, net worth, The Giving Pledge registry
How much sourced public record we hold about this person — net worth, SEC filings, foundation 990s, news coverage, Wikidata. It measures our coverage, not how open the person is. Each further kind of record scores higher, up to eight. Political donation records matched to a person by name alone are not counted: they may belong to someone else with the same name. From October 7, 2026, our own AI-written summary and the profile photo are not counted either — neither is a public record — so grades that leaned on them moved down that day.
Data: SEC EDGAR, ProPublica 990s, GDELT / NewsAPI, Wikidata
Formula (v2): Giving score = 65% x Philanthropy + 35% x Data coverage
Scored on 10/16/2026 on a 0–100 scale. The score uses only the signals we have populated data for. Goal Impact, Controversy, and Community Approval are deferred until that data exists — Phase 1 goal adoption, controversy detection, and community votes respectively.
All data is sourced from public records. Each section links to its original source.