• John Spellar, the winning Labour candidate, would later serve as MP for Warley West.
• Roger Gale would later serve as MP for North Thanet.
• Stephen Ridley, a solicitor, ran on a campaign of introducing works councils to give workers more say in their jobs and improving local amenities.^[1]
• Ian Anderson emerged as the leading figure of the Flag Group wing of the National Front and later became leader of the party.
• Peter Sheppard ran on an anti-National Front, anti-Margaret Thatcher platform. He was chairman of the All Birmingham Committee Against Racism and Fascism.^[2]
• Bill Boaks, a serial independent candidate during the 1970s who frequently managed only double figure vote totals, was standing in his final by-election (he was also a candidate in the Peckham by-election, which was held simultaneously).

The result gave the Labour Party its first gain in a by-election in Britain since 1971. Yet while Labour had regained the seat which it had lost in 1979, the Conservatives were reported to be delighted at only narrowly losing given that the seat had been their third most vulnerable based on the 1979 results. Norman Tebbit, then a Conservative Cabinet minister, noted his party had come "within an ace of holding one of our most marginal constituencies" and argued that the results in Northfield and the by-election held on the same day for the Peckham constituency showed that the intervention of the Alliance allowed Labour to win.^[4] Writing in The Glasgow Herald, political journalist Geoffrey Parkhouse argued that winning Northfield saved Labour leader Michael Foot "from disaster", but the closeness of the result meant it was a "desperate victory" for him. He also argued that the results showed that Mrs Thatcher's Government was on course to win the next election, but that the Alliance's potential to take votes from the Conservatives could yet prevent them from gaining an overall majority.^[4]