Gavin Newsom Family Tree: The Story Behind California's Governor

Gavin Christopher Newsom, born 10 October 1967 in San Francisco, California, USA, is the 40th Governor of California (from 7 January 2019) — former San Francisco Mayor (2004–2011); Lieutenant Governor of California (2011–19).

The Family's Roots: An Irish-American San Francisco Family

The Newsom family has deep San Francisco roots; closely linked to the Getty and Pelosi dynasties.

His Parents

Father: William Alfred Newsom III (1933–2018) — California Court of Appeal judge; close friend of and trustee for J. Paul Getty (oil tycoon).

Mother: Tessa Thomas Menzies — homemaker; later worked as a private chef.

His Sister

Hilary Newsom, born 1969 — Gavin's younger sister.

His First Wife: Kimberly Guilfoyle

Kimberly Guilfoyle, born 9 March 1969 — TV personality; former Fox News host; engaged to Donald Trump Jr. (2018–24); now nominated as US Ambassador to Greece by Trump. Married Gavin on 8 December 2001; divorced 2006.

His Wife: Jennifer Siebel Newsom

Jennifer Lynn Siebel Newsom, born 11 March 1974 — actress and documentary filmmaker. Married Gavin on 26 July 2008.

Their Children

Montana Tessa Newsom, born September 2009 — daughter.

Hunter Siebel Newsom, born June 2011 — son.

Brooklynn Newsom, born July 2013 — daughter.

Dutch Newsom, born February 2016 — son.

The Newsom Family Tree at a Glance

Father: William Newsom III (1933–2018) — California judge; Getty trustee.

Mother: Tessa Menzies Newsom.

Sister: Hilary Newsom (b. 1969).

First Wife: Kimberly Guilfoyle (b. 9 March 1969; m. 8 December 2001, div. 2006).

Wife: Jennifer Siebel Newsom (b. 11 March 1974; m. 26 July 2008).

Children: Montana Tessa (b. September 2009); Hunter (b. June 2011); Brooklynn (b. July 2013); Dutch (b. February 2016).

Distant aunt-in-law: Nancy Pelosi (Gavin's aunt is married to Nancy Pelosi's brother-in-law; the families have been close for decades).

Gavin Newsom:

  • Born 10 October 1967, San Francisco
  • Redwood High School (Larkspur); Santa Clara University (BA Political Science 1989)
  • Founded the PlumpJack Group wine and hospitality (1992) — funded with help from Gordon Getty
  • San Francisco Board of Supervisors: 1997–2003
  • Mayor of San Francisco: 8 January 2004 – 11 January 2011 — famously authorized same-sex marriages from 12 February 2004 (over 4,000 ceremonies before state Supreme Court ordered halt)
  • Lieutenant Governor of California: 2011–2019
  • 40th Governor of California: from 7 January 2019 — survived recall election 14 September 2021
  • Frequently mentioned as a 2028 Democratic presidential candidate

What the Newsom Family Story Teaches Us

A judge father who managed J. Paul Getty's trust. A homemaker mother. A sister. A first marriage to a Fox News host now linked to the Trump family. A second marriage and four children. A career that combined wine business and California politics.

For every family — large or small, famous or otherwise — the Gavin story carries the same lesson. Some marriages cross political tribes — Gavin's first wife is now nominated as a Trump-administration ambassador.

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