Between 1983 and 2005, the seat was a bellwether; in 2010 and 2017 the seat leaned more to the left than the overall result.
The seat has been relative to others a marginal seat since 2001, as well as a swing seat, as its winner's majority has not exceeded 8.6% of the vote since the 15.9% majority won at that year's general election. The seat has changed hands twice since then.
1950-1955: The County Borough of Derby wards of Abbey, Babington, Becket, Bridge, Derwent, Friar Gate, King's Mead, and Rowditch.
1955-1974: The County Borough of Derby wards of Abbey, Babington, Becket, Bridge, Derwent, Friar Gate, King's Mead, and Rowditch, and the parish of Chaddesden in the Rural District of Shardlow.
1974-1983: The County Borough of Derby wards of Abbey, Allestree, Breadsall, Chaddesden, Darley, Derwent, Friar Gate, Mickleover, and Spondon.
1983-2010: The City of Derby wards of Abbey, Allestree, Breadsall, Chaddesden, Darley, Derwent, Mackworth, and Spondon.
2010–present: The City of Derby wards of Abbey, Chaddesden, Darley, Derwent, Littleover, Mackworth, and Mickleover.
Many constituency boundaries changed for the 2010 general election; this seat changed quite significantly, which made the seat less of a Labour Partysafe seat based on council results for electoral wards.
The constituency covers a largely residential area immediately north of Derby city centre, including some of the city’s most affluent suburbs, as well as some of its council housing, though much of this is former council housing in private ownership. Unemployment is below the national average. Average incomes are above the national average.
A seat contested relatively closely between the two largest parties since 1950, Derby North was held consecutively by the Labour Party's Clifford Wilcock, Niall MacDermot, and Phillip Whitehead.[n 2] At the 1979 election it was covered by the BBC as the bellwether seat as the 41st of 41 seats that the Conservative Party needed to win; in that year it stayed Labour (but the Conservatives won the election). Its exit poll was a central point of discussion of the BBC's election night coverage.
Labour's Bob Laxton defeated Knight in 1997 and held the seat until retiring in 2010, when the seat was held for Labour by Chris Williamson. In 2015 Amanda Solloway, a Conservative, gained the seat with a swing of 0.8%. The 2015 result gave the seat the second-most marginal majority (measured by percentage) of the Conservative Party's 331 seats. Williamson regained the seat in 2017. He was subsequently suspended from the Labour Party, and was blocked in November 2019 from running as a Labour candidate at the following election; he resigned from the party and stated his intention to run as an independent.