There aren't many options for editing subtitles on the Mac, but fortunately Subtitles theEditor is a fairly comprehensive tool, providing you everything you need to add, edit, or remove subtitles.

Comprehensive Tools

For the most part, this app provides just about every type of function you might require of a subtitle editor, and certainly from anything in this price range. You can add, edit, and remove subtitles. Convert subtitle files between .SRT and .SUB (and vice versa). Easily fix overlapping subtiles, change the frame rate, quickly find a specific word, or search and replace a word. Subtitles theEditor allows you to re-sync subtitles in less than two minutes, and also boats automatic language translation.

A Bit Difficult

As fully featured as it is, Subtitles theEditor can be a bit difficult to use. The user interface has some issues, such as it being unclear where you're supposed to click to enter text. And it can be a bit daunting to figure out how to use the app at first. It's also worth noting that there have been no updates for a long time, and the developer appears to have abandoned the software. This also means some of the latest file formats aren't supported.