Unfortunately, the iPhone doesn’t sync bookmarks directly from Firefox. There is a workaround though. To import Bookmarks from Firefox, you first will have to import them into Safari, then sync them into your iPhone.

Mac users can perform the following steps:

1. Open Safari and select File > Import Bookmarks…

2. Find your bookmark file under your Home folder, then Library > Application Support > Firefox > Profiles > user folder.

3. Double-click the file called bookmarks.html.

4. Connect your iPhone and select it on the left pane in iTunes.

5. Click on the Info button.

6. In the Web Browser section, turn on Sync Safari bookmarks and click Apply.

Windows users can perform these steps:

1. Open Firefox and select Bookmarks > Organize Bookmarks.

2. Bookmarks Manager will open. Select File > Export…

3. Save the bookmarks.html file to your Desktop.

4. Open Safari and select File > Import Bookmarks…

5. Double-click the bookmarks.html file on your desktop.

6. Connect your iPhone and select it on the left pane in iTunes.

7. Click on the Info button.

8. In the Web Browser section change the option for Sync bookmarks from to Safari.