If you plan to play standing up, yes you do. A good-quality strap will keep the guitar stable while you play. Ensure your strap isn’t too narrow. A wide strap with some padding is far more comfortable than a narrow one without padding.
Consider buying a strap lock for your guitar, acoustic or electric. A strap lock will prevent the strap from departing from the guitar, often causing damage to the instrument.
The site administrator for Guitar Advice, Pete has been playing guitars since childhood. He's into both electrics and acoustic but now prefers electric. He plays guitars most days and enjoys doing it more than ever. Reading and writing about guitars is what he loves to do.