Logrolling is the trading of favors, or quid pro quo, such as vote trading by legislative members to obtain passage of actions of interest to each legislative member. In organizational analysis, it refers to a practice in which different organizations promote each other's agendas, each in the expectation that the other will reciprocate. In an academic context, the Nuttall Encyclopedia describes logrolling as "mutual praise by authors of each other's work". Where intricate tactics or strategy are involved, the process may be called horse trading.

Logrolling is a political process where politicians trade support for one issue or piece of legislation in exchange for another politician's support. There are three types of logrolling: logrolling in direct democracies, implicit logrolling, and distributive logrolling, with the latter being the most prevalent in democratic systems. The concept originates from neighbors assisting each other with moving logs and was first applied to legislation by American frontiersman Davy Crockett.

Logrolling is driven by individual choices and is considered mutually beneficial for politicians. It allows for diverse legislative agendas to be represented and helps in reaching the highest valued outcome, even for minority views. However, logrolling may result in inefficient outcomes if the sum of the total benefit of the legislation for all voters is less than the cost of the legislation itself. The process plays a significant role in forming minimum winning coalitions, ensuring the passage of legislation in a democracy.

An example of logrolling in U.S. history is the Smoot-Hawley tariff in 1930. Omnibus bills, containing various clauses to satisfy all parties, can be an alternative to logrolling. However, these can be large and complex, like the Patient Protection and Affordable Care Act. Logrolling can give special-interest groups a voice, which may not always be in the majority's best interest. Critics argue that legislators engaging in logrolling may prioritize personal benefits over the general welfare, leading to higher government spending and taxation.

In Belgium, wafelijzerpolitiek (waffle-iron politics) is a form of logrolling that has resulted in overfunded projects, contributing to the country's high debt. The practice has decreased after the 1988 state reformation. Simple referendums can help avoid logrolling, as voters cannot easily trade votes on reciprocal favors. While some view vote trading as morally reprehensible, logrolling is often seen as necessary within democratic systems, as long as constitutional rules are observed.