交互设计，又称互动设计，(英文Interaction Design, 缩写 IxD 或者 IaD),是定义、设计人造系统的行为的设计领域。人造物，即人工制成物品，例如，软件、移动设备、人造环境、服务、可佩带装置以及系统的组织结构。交互设计在于定义人造物的行为方式(the "interaction",即人工制品在特定场景下的反应方式)相关的界面。

交互设计师首先进行用户研究相关领域，以及潜在用户，设计人造物的行为，并从有用性，可用性和情感因素（usefulness, usability and emotional）等方面来评估设计质量。

In design, human–computer interaction, and software development, interaction design, often abbreviated IxD, is defined as "the practice of designing interactive digital products, environments, systems, and services." Like many other design fields interaction design also has an interest in form but its main focus is on behaviour. What clearly marks interaction design as a design field as opposed to a science or engineering field is that it involves synthesising and imagining things as they might be, more so than focusing on how things are.