Derek Francis Quigley (born 31 January 1932) is a former New Zealand politician. He was a prominent member of the National Party during the late 1970s and early 1980s, and was known for his support of free market economics and trade liberalization. Quigley left the National Party after clashing with its leadership, and later co-founded the ACT New Zealand party.

Quigley was born in Waikari, a small town in the northern Canterbury region. He was educated in Christchurch, attending Canterbury University. Initially, Quigley worked as a farmer, but later gained a law degree and practiced as a lawyer.

After holding a number of internal party positions, Quigley stood as the National Party's candidate for the Rangiora seat in the 1975 election. The seat had been taken from National by Kerry Burke of the Labour Party at the previous election, but was successfully won back by Quigley. After three years as a backbencher, Quigley was appointed to Cabinet, and held a number of ministerial roles.

Quigley rapidly earned the hostility of senior National Party figures, however, with his criticism of the government's economic policies. The Prime Minister of the day, Robert Muldoon, favoured decidedly interventionist policies, but Quigley preferred a more laissez-faire approach, and considered Muldoon's interventionism to be contrary to the traditional spirit of the National Party. In 1981, Quigley contested the deputy leadership of the party, despite Muldoon openly saying that he could not work with him. Quigley's main opponent (and Muldoon's strong favourite) was Duncan MacIntyre, a long-serving Muldoon loyalist. Quigley was defeated.

A week after Quigley lost the deputy leadership race, he was dismissed by Muldoon as Associate Finance Minister, reducing his ability to effectively criticise Muldoon's economic policies. Quigley nevertheless continued his attacks. In June the following year, he made a public denunciation of the government's policies, saying that the state should have a passive role in the economy. Muldoon and his allies reacted furiously to this public criticism, and Quigley was given the choice of either giving a public apology or resigning from Cabinet. He chose to resign. At the 1984 election, he resigned from politics altogether, becoming a business consultant.

In 1995, however, Quigley re-entered the political arena, joining forces with Roger Douglas to form the ACT New Zealand party. The new MMP electoral system, which made it easier for smaller parties to win seats, convinced Quigley that a strongly free-market party could indeed be successful. In the 1996 election, the first conducted under MMP, Quigley was returned to Parliament as an ACT list MP. At the 1999 election, however, Quigley retired from politics a second time, and has not returned to Parliament. On 2 December 2004, both he and Roger Douglas announced that they were stepping down as patrons of ACT, saying that they wished to have more freedom to publicly disagree with the party.