**Regression** could refer to:

- Regression (psychology), a defensive reaction to some unaccepted impulses
- Regression analysis, a statistical technique for estimating the relationships among variables. There are several types of regression:
- Linear regression model
- Simple linear regression
- Logistic regression
- Nonlinear regression
- Nonparametric regression
- Robust regression
- Stepwise regression

- Regression toward the mean, a common statistical phenomenon
- Regression (economics), Ludwig von Mises' theorem that tries to explain why money is demanded in its own right
- Software regression, the appearance of a bug which was absent in a previous revision
- Regression testing, a software testing method which seeks to uncover regression bugs
- Infinite regress, a problem in epistemology
- Marine regression, coastal advance due to falling sea level, the opposite of marine transgression
- Regression (medicine), a characteristic of diseases to express lighter symptoms without disappearing totally
- Age regression in therapy
- Past life regression, a process claiming to retrieve memories of previous lives