PP

PP, pp or Pp may refer to:

Arts and entertainment

 * Pianissimo, a music term meaning very quiet, from musical dynamics
 * Production code for the 1967–1968 Doctor Who serial The Enemy of the World
 * Police Procedural - a subgenre of procedural drama and detective fiction

Political parties

 * Patriotic Party (Guatemala)
 * People's Party (Spain) (Partido Popular)
 * Pirate Party (Global)
 * Progressistas (Brazil) (Progressistas)
 * Progressive Party (Iceland)
 * People's Partnership (Trinidad and Tobago)
 * We Continue the Change (Bulgaria) ("Prodalzhavame promyanata")

Other businesses and organizations

 * Pancasila Youth (Pemuda Pancasila), an Indonesian paramilitary organization
 * PediaPress, a German software company
 * Planned Parenthood, a reproductive health organization
 * Philipp Plein, logo
 * PayPal, an online payments company

Religion

 * pp, Papa Pontifex, post-nominal used by popes

Biology and medicine

 * Vitamin PP or nicotinamide
 * Paliperidone palmitate, an antipsychotic medication
 * Pancreatic polypeptide, a polypeptide secreted by PP cells
 * PP cell or pancreatic polypeptide cell
 * pro parte, abbreviated p.p., for a type of synonymy in taxonomy

Computing

 * PP (complexity), a probabilistic polynomial time complexity class
 * PP-format (Post Processing Format), a file format for meteorological data
 * PP X.400, an e-mail protocol
 * Plug and play (P&P), a property of a peripheral device
 * Microsoft PowerPoint, a presentation program

Mathematics

 * P–P plot, a probability plot, in statistics
 * Percentage point, in business writing and statistics
 * Process performance index (Pp)
 * Presque partout (almost everywhere), in measure theory and analysis. (This is always lower case -- 'pp'.  In English 'ae' is often used instead.)

Other uses in science and technology

 * Paris Principles (cataloging), a theoretical foundation for the creation of bibliographical cataloging rules for libraries
 * Walther PP, a pistol
 * Length between perpendiculars ("pp" or "p/p"), the length of a ship
 * Peak to peak (p–p) amplitude of a signal
 * Polypropylene, a common plastic polymer
 * Proton–proton chain, in nuclear physics and astronomy

Other uses

 * p.p., Per procurationem, when signing on behalf of another
 * pp, pages (of a book), an example of the convention of doubling the letters in the acronym to indicate plural words, see Acronym and initialism
 * Percy Pig, a British brand of pig-shaped fruit-flavoured confectionery products
 * Peso Pluma, musician
 * Pierre Poilievre, Conservative politician in Canada.
 * PinkPantheress, singer