Yep. Assuming these are iTunes movies or movies loaded into iTunes. Airplay will let you stream them (and you should have access to them in iCloud through the AppleTV as well).
Additionally, if you have a i5/i7 series MBP, you'll be able to use Airplay Mirroring to send your MBP screen to your TV.
Connecting the MacBook directly to the tv is the easiest, but then it is tethered which is a pain.
With an AppleTV and home sharing you can play any movies loaded in iTunes directly as long as the MacBook is on and connected to the same network as the AppleTV.
To play movies not loaded in iTunes you need a work around. AirPlay mirroring is not likely to prove satisfactory for movies, so you'll need a third party app. Beamer is one app that claims to do this.
I use HandBrake to convert videos that aren't compatible with iTunes. I use iDentify to manage metadata. With my TV shows and movies in my iTunes library, I can watch anything I want on my AppleTV.