Giving your forum an entirely new look and feel is easy — just download one of these great themes! There are even themes for the admin control panel.
Projects in Light

Flatty - A nice & simplistic flat theme for MyBB.

Fully responsive, modern & multicolor theme for MyBB 1.8 (Documentation included)

Focus is a clean and Elegant Flat MyBB theme which can be used by all sort of community users, one of the cool features of this theme is shrinking header on scroll. Focus MyBB Theme has been tested thoroughly on all browsers.

Free Responsive MyBB Theme - NetPen

A simple variant of the default MyBB theme.

Responsive and multicolor ACP theme in Flat Design

Responsive Modern Mybb Themes 1.8.29

Roundo gives a new modern look to MyBB. This is a modern, flat, minimalist, responsive theme that can be used for free on your forum.

Classic Blue is remake of a old theme TheTechGame.com used back in 2011. This theme is a nice white and blue theme for almost any type of forum.

The responsive version of MyBB's default theme with mobile friendly and with new look .
MT MODERN THEME

Elegant, General dark and light theme for mybb

A MyBB GitHub like theme

A flat and simple responsive premium theme for free now!

eXe is a mobile compatible and desktop mybb theme.Applies to Mybb versions 1.8.X

Duende V3 - Fully responsive, tons of improvements

Seriforn is a light MyBB theme, which is highly compatible with most of the popular MyBB 1.8.x plugins.

io Theme is a minimal, simple and free MyBB theme.

Fully-responsive, elegant, Bootstrap-driven MyBB theme

Lightly designed theme. Simple and fast.