Create a caption in Keynote on iPhone
You can use a text box to add a caption or label to an image, table, shape or other object.
Tap
, tap 
, then tap Text in the Basic category.A text box with placeholder text appears on the slide.
Drag the text box to where you want it.
If you can’t move the text box, tap outside the box to deselect the text, then tap the text once.
Double-tap the placeholder text, then type the caption.
If the text doesn’t fit, drag the selection handles on the text box. If you can’t see selection handles, tap outside the box, then tap the text once.
Do any of the following:
Change the font, font size, text colour or paragraph style: Tap
, tap Text, tap the font size and name, then choose options.Change the look of the text box: Tap
, tap Style, then tap one of the six text box styles. You can use the other controls to change the colour of the text box, add a shadow to it and make other adjustments.
To group the caption with the object so they stay together, tap the object once, then hold your finger on the object while you tap the text box.
Lift your fingers, then tap Group.
If you want to use the same formatting for all captions in your presentation, you can create a paragraph style for captions so you can easily apply the style to all the captions in your presentation.
Note: To learn how to add captions to an image gallery, see Add an image gallery in Keynote on iPhone.