David Caygill is a former New Zealand politician. He was an MP from 1978 to 1996, representing the Labour Party. He served as Minister of Finance between 1989 and 1990.

Caygill was first elected to Parliament in the 1978 elections as MP for St Albans, an electorate in Christchurch. After the 1984 elections, when Labour came to power, Caygill aligned himself with Roger Douglas, the controversial Minister of Finance. Douglas, Caygill, and Richard Prebble were together dubbed "the Troika", and were responsible for most of the economic reform undertaken by the Labour government. The reforms, which were based around free market economic theory, were unpopular with many traditional Labour supporters, but Caygill managed to avoid the worst of the condemnation directed towards Douglas and Prebble.

When Douglas was finally forced to resign by the Prime Minister, David Lange, Caygill was appointed Minister of Finance in his place. After Lange himself had resigned, Caygill retained his position under both Geoffrey Palmer and Mike Moore, Lange's short-lived successors.

In 1991, a year after the Labour Party had lost office, Caygill was replaced as finance spokesperson by Michael Cullen, who was more moderate in his economic policies. Caygill continued to hold a senior position in the party, however, and when Helen Clark became leader in 1993, Caygill replaced her as deputy leader. At the 1996 elections, however, Caygill finally retired from Parliament. He was replaced as deputy leader by Michael Cullen.

After leaving politics, Caygill returned to his original occupation, law. For some time, he was a partner at Buddle Findlay, a prominent law firm. He also worked for a number of government bodies, being chair of the Accident Compensation Corporation and chair of a ministerial inquiry into the New Zealand electricity market.