A handjob is a sex act, performed as either foreplay or as non-penetrative sex, that involves the manual stimulation of a man's penis or scrotum by another person to induce an erection for sexual pleasure, sexual arousal and sometimes resulting in orgasm and ejaculation.

A handjob can be sexually arousing for both participants and may be an erotic and physically intimate act of its own. A woman in a heterosexual relationship may give her male partner a handjob so as not to engage in penetrative sexual activity. Besides avoiding the risks associated with sexual penetration, such as sexually transmitted infections (STIs) or pregnancy from penile-vaginal sex, some people engage in non-penetrative sex to preserve virginity.^[1]

For circumcised people, lubrication is commonly used, while in uncircumcised people, a handjob is performed by moving the foreskin back and forth.

In massage parlors, a masseuse, whether as part of the massage itself or directly after it, may perform a handjob on their customer; this is known by the euphemism "happy ending".^[2][3]

An investigation by Time Out New York in January 2011 found many New York City massage parlors advertising "sensual massage" and providing handjobs. The parlors charged from $60 to $160, with an extra tip for the sex workers (usually $40) for a massage and manual "happy ending". Most of the massage parlors reviewed were "rub and tug joints" where handjobs were the only sexual services provided, and there was a strict policy of the male clients not touching the female workers.^[4]