Samsung has started rolling out Filmmaker Mode via a firmware update for its 2020 "QLED" LCD TVs. It is available now in the US but still pending in Europe. Update: Now also available in Europe.
Filmmaker Mode for Samsung TVs
Filmmaker Mode was announced in August 2019 by the UHD Alliance. It is a new picture mode for TVs that aims to "preserve creative intent" by disabling things like motion smoothing and respecting the frame rate, colors, more. The initiative is backed by directors such as Christopher Nolan, Ryan Coogler, Martin Scorsese, and James Cameron.
Filmmaker Mode is available as a new picture mode from the picture menu on Samsung 2020 "QLED" LCD TVs after installing firmware update 1301.5. The update is compatible with Samsung Q950T, Q900T, Q850T, Q800T, Q90T, Q80T, Q70T, and LS03T (The Frame), according to the release notes.

FlatpanelsHD has yet to try Filmmaker Mode on Samsung TVs but we have examined it on LG CX (review) and Panasonic HZ1000 (review) where it is largely identical to the already available 'Cinema' / 'Professional' picture modes in the two TVs, respectively. Vizio and Philips are also launch partners but have yet to enable it.
Also read: Review: Samsung Q95T / Q90T
Samsung notes that Filmmaker Mode can be enabled manually or automatically if it detects the corresponding "flag" in the content. This flag has not yet been implemented on discs or streaming services so at this time Filmmaker Mode remains a manual option. It works with both SDR and HDR content.
The update is rolling out now in the US but still pending in Europe (Update: now also available in Europe as firmware ver. 1304). If you are not seeing it via the TV's built-in update function you can go to Samsung's support page here to download it manually onto a USB thumb drive.
USA: Firmware version 1301.5 can be downloaded from Samsung support here
Europe: Update: Firmware version 1304 with Filmmaker is now also available in Europe from Samsung support here.
Samsung 2020 TVs with Filmmaker Mode
FlatpanelsHD