He is the author of the two Sunday Times Best Sellers: Values, Voice and Virtue: The New British Politics and National Populism: The Revolt Against Liberal Democracy (co-authored with Roger Eatwell).

[5] His research has covered a range of topics, including Brexit, British politics, the implications of rising ethnic diversity in the West, and the future of Europe.

[13] In 2018, Goodwin published National Populism: The Revolt Against Liberal Democracy (co-authored with Roger Eatwell), which explained factors that contributed to Brexit.

[16][17] Goodwin is on the advisory panel of the Free Speech Union,[18][19] a group that seeks to "counter Twitter mobs that drown out opinions they dislike".

[39][non-primary source needed] In 2023, Gerry Hassan wrote that "Goodwin is the populist right's academic of choice, but it seems to have escaped his notice that in the past half century right-wing Tory Governments have been in office for three-quarters of the time.

[8] Goodwin and his National Populism co-author Roger Eatwell have argued about the United States that political polarisation has been caused by "an increasing fixation or near-total obsession among Democrats and the liberal left with race, gender and 'diversity'".

[2] In 2018, Goodwin along with other commentators including Eric Kaufmann, Claire Fox, Trevor Phillips, and David Aaronovitch was due to take part in an event titled "Is Rising Ethnic Diversity a Threat to the West?"

Some researchers argued that the event would encourage "normalisation of far right ideas" and criticised the framing of the title;[47][48][49] the debate was retitled "Immigration and Diversity Politics: A Challenge to Liberal Democracy?

Goodwin argues that left-wing parties, including Labour, have moved away from their foundational principles, increasingly focusing on identity politics, especially concerning sex and gender.

[58] For The Atlantic, Helen Lewis wrote that Goodwin gave "a typically doomy speech", which "segued into 10 minutes of pure populist beat poetry".

"[62] During the 2024 United Kingdom riots that followed the 2024 Southport stabbing, Goodwin criticised commentators who labelled the groups engaged in the violence as "far right", writing on X that there had been a "concerted & most likely coordinated effort by the elite class to inflate 'far right' to stigmatise & silence millions of ordinary people who object to mass immigration and its effects".

Conservative commentator Tim Montgomerie called Goodwin's posts “incendiary”[5] and ITV News' Joel Hills asked "Matt, are you still at the University of Kent?

[8] On 27 May 2017, Goodwin predicted that the Labour Party would not reach 38 per cent of the vote in the 2017 United Kingdom general election and said he would eat his book if they did.

However, Will Jennings of the University of Southampton notes that when speaking at an event at the London School of Economics on the day of the Brexit referendum, Goodwin actually predicted a two-point Remain win.

[65] In 2014, aged 33, Goodwin was awarded the Richard Rose Prize by the Political Studies Association, which is given to one early-career academic each year for their contribution to research.