MLA does not provide exact guidance for handling citations and a Works Cited page in PowerPoints. However, there are still best-practices recommended by Purdue Owl and several universities.
Labelling figures and tables is more straight forward.
The easiest way to handle citations and references is to follow the same rules you would for a paper, and do an in-text citation within the sentence or bullet point, and have a Works Cited page on your last slide.
If for design reasons, you would prefer to put a complete reference on each slide, you can do that and omit a separate Works Cited page. However, keep in mind that if you refer to more than one source on a single slide, including the references on that slide will make it very text-heavy.
In addition to the examples below, I've included a link to Purdue Owl's MLA libguide, Holgate Library's PowerPoint in MLA format libguide, and a link to our Cite MLA Style libguide.
Here are some examples:
Follow the standard MLA rules for in-text citations.
Works Cited page:
Include a separate Works Cited page. If you don't have room to double space, that's ok. If you have to use bullets, so you can't include a hanging indent, that's ok.
Number the table. Spell out the word "table". Use an Arabic number (not spelled out). On the next line, include a caption, title or brief description.
Underneath the table, include the source information, beginning with Source:. You don't have to include it in your Works Cited page, unless you cite it on another slide.
Illustration or Figure Example:
Underneath the picture, include the figure number. Capitalize the word "figure". Use a "." if you shorten the word, and use an Arabic numeral (don't spell out the number). On the same line, include a caption, title or brief description.
Ask the MLAfaqworks-cited list
How do I cite an image from a slide presentation on the Web or from a lecture I attend?
Cite an image from a slide presentation on the Web the same way you would cite an image on a Web page. Indicate the slide and its number, either in the optional-element slot at the end of the entry or in a parenthetical citation in your text:
Benton, Thomas Hart. Instruments of Power. 1930–31. The Met, Metropolitan Museum of Art, www.metmuseum.org/blogs/now-at-the-met/from-the-director/2012/benton/slideshow. Slide 1.
Thomas Hart Benton’s panel Instruments of Power is part a larger mural (slide 1).
Cite an image from a slide presentation that you viewed in person by providing the name of the presenter as the author if the author created the image in the slide. Then provide the title of the image as the title of the source. Provide the name of the presentation or the name of the class as the title of the container. Then provide the date and the location. Indicate the slide and its number in the optional-element slot at the end of the entry or in a parenthetical citation in your text:
If the presenter did not create the image in the slide, provide information about the original, if known: