Yes, all of your old Apple Watch bands are compatible with the Apple Watch Series 7

Contrary to some pre-event rumors, the redesigned Apple Watch Series 7 will not require new Watch bands, and will remain compatible with all previous ones.Apple Watch Series 7 bands are compatible with previous WatchesApple Watch Series 7 did not get the flat-edge redesign that was expected, but it will come with a larger body. Conflicting leaks and rumors prior to the unveiling suggested that the new 41mm and 45mm size Apple Watches would therefore require new bands. Read more...