The Quietly Confident Quartet was the self-given name of the Australian men's 4 × 100 metres medley relay swimming team that won the gold medal at the 1980 Summer Olympics in Moscow.

In mathematical optimization, a quadratically constrained quadratic program (QCQP) is an optimization problem in which both the objective function and the constraints are quadratic functions.

The Quantum Chromodynamic Vacuum or QCD vacuum is the vacuum state of quantum chromodynamics (QCD). It is an example of a non-perturbative vacuum state, characterized by non-vanishing condensates such as the gluon condensate and the quark condensate in the complete theory which includes quarks.

Quark matter or QCD matter refers to any of a number of theorized phases of matter whose degrees of freedom include quarks and gluons.

The QClash is the name given to the Australian rules football rivalry match between the Brisbane Lions and Gold Coast Suns, who both participate in the Australian Football League (AFL).

QCT is a provider of data center hardware and cloud solutions that are used by hyperscale data center operators, such as Facebook and Rackspace.In conjunction with its parent company, Quanta Computer, QCT sells approximately one out of every seven server manufactured in the world.QCT is an early contributor to the Open Compute Project, a non-profit organization launched by Facebook engineers to open source the designs of data center products.

Qiqihar (Chinese: 齐齐哈尔) is the second largest city in the Heilongjiang province of China, located in the west central part of the province.

Qaqortoq, formerly Julianehåb, is a town in the Kujalleq municipality in southern Greenland, located near Cape Thorvaldsen.

In statistics, a Q–Q (quantile-quantile) plot is a probability plot, which is a graphical method for comparing two probability distributions by plotting their quantiles against each other.