Chris Evans diumumkan telah dicasting sebagai Buzz Lightyear manusia pada pengumuman proyek pada bulan Desember 2020.<ref name="LightyearAnnouncement" /> Evans wasadalah thepilihan firstpertama anddan onlysatu-satunya choiceyang MacLanedimiliki hadMacLane foruntuk Buzz.<ref name="MacLanesChoice">{{Cite web |date=October 27, 2021 |title='Lightyear' Director Angus MacLane on Making the Action Sci-Fi Movie That Buzz Lightyear Is Based On |url=https://collider.com/lightyear-director-angus-maclane-pixar-interview-buzz-lightyear/ |url-status=live |archive-url=https://web.archive.org/web/20211030054510/https://collider.com/lightyear-director-angus-maclane-pixar-interview-buzz-lightyear/ |archive-date=October 30, 2021 |access-date=November 9, 2021 |website=[[Collider (website)|Collider]]}}</ref> Dia mengunjungi kantor Pixar suatu hari dan mereka memberinya proyek selama kunjungan. Evans segera menerima tawaran itu, mengingat kecintaannya pada animasi.<ref name="Fandango" /> [[Taika Waititi]] was reported to have been cast in an undisclosed role in November 2021.<ref name="waititi">{{Cite web |last=Shuler |first=Skyler |date=November 11, 2021 |title=Exclusive: Taika Waititi to Voice a Character in Pixar's 'Lightyear' |url=https://thedisinsider.com/2021/11/11/exclusive-taika-waititi-to-voice-a-character-in-pixars-lightyear/ |url-status=live |archive-url=https://web.archive.org/web/20211111170823/https://thedisinsider.com/2021/11/11/exclusive-taika-waititi-to-voice-a-character-in-pixars-lightyear/ |archive-date=November 11, 2021 |access-date=November 11, 2021 |website=The DisInsider}}</ref> [[Keke Palmer]], Dale Soules, [[Uzo Aduba]], [[James Brolin]], Mary McDonald-Lewis, Efren Ramirez dan [[Isiah Whitlock Jr. diberitakan telah berperan dalam peran pendukung pada Februari 2022.<ref name="ligthtyearvoicecast">{{Cite web |last=Bastos |first=Margarida |date=November 11, 2021 |title='Lightyear' Full Voice Cast Includes Taika Waititi, Keke Palmer, James Brolin, and More |url=https://collider.com/lightyear-voice-cast-taika-waititi-keke-palmer-james-brolin/ |url-status=live |access-date=February 8, 2022 |website=Collider}}</ref>