Jabarkan Pemasaran dari Joker (film 2019)

Todd mempromosikan film ini lewat mengunggah sejumlah gambar di feed Instagram-nya. Pada 21 September 2008, Todd meluncurkan rekaman uji berupa Joaquid yang mengenakan kostum Joker, dengan "Laughing" oleh The Guess Who mengalun di rekaman itu. At CinemaCon on April 2, 2019, Phillips unveiled the first trailer for the film, which was released online the following day. The trailer, prominently featuring the song "Smile" performed by Jimmy Durante, generated positive responses, with some commentators comparing it to Taxi Driver and Requiem for a Dream and praising Phoenix's performance. Writers described the trailer as dark and gritty, with ComicBook.com Jenna Anderson feeling it appeared more like a psychological thriller than a comic book film. Mark Hamill, who has voiced the Joker since the 1992 cartoon Batman: The Animated Series, expressed enthusiasm in a Twitter post. Conversely, io9 Germain Lussier said the trailer revealed too little and that it was too similar to photos Phillips posted on Instagram. While he still believed it exhibited potential, Lussier overall thought the trailer was not "a home run." The trailer received over eight million views in the first few hours of release.

Pada 25 Agustus 2019, Todd mengunggah enam penggoda singkat yang menampilkan kilatan yang mengungkap trailer kedua akan diunggah pada 28 Agustus. Filmmaker Kevin Smith commended the trailer, stating he thought the film "would still work even if [DC Comics] didn't exist" and praising its uniqueness. Overall, Deadline Hollywood estimated that Warner Bros. spent $120 million on promotion and advertisements.