Born in Hāwera on 8 March 1973, Brewer attended Wanganui Collegiate School (1986 to 1990) and Massey University (1991 to 1994) where he graduated with a Bachelor of Arts Double Major: History & Sociology.

He was then employed by Parliamentary Services in Wellington, as a Writer in the National Party's Research Unit and as a Press Secretary to the Leader of the Opposition.

[8] A former journalist, Brewer is a member of the New Zealand National Party and worked as press secretary to Jenny Shipley, John Banks and Rodney Hide.

Following the announcement of John Key's pending resignation as a member of parliament, it was speculated that he was considering standing in the electorate, but he ruled it out in early January 2017 citing family, business and local board commitments.

[13] During the 2023 election that was held on 14 October, Brewer won with a wide majority of 11,192, flipping the seat back to National and ousting first-term incumbent Vanushi Walters.

[14] After an election night celebration, Brewer was accused of making an inappropriate comment in his speech, declaring that his win was a victory for “stale, pale, males”.