Will the 05 GMC Sierra taillights fit an 05 GMC Sierra Denali?

Yes, the taillights from a 2005 GMC Sierra will fit a 2005 GMC Sierra Denali, as both models share the same body style and taillight design. However, it's always a good idea to check for any specific trim differences or features that might affect compatibility, such as wiring or additional functions like LED lights. If you're considering a replacement, ensure that the part numbers match for the best fit.