Yes. You can play the Campaign alone. In the solo preview, you control Marcus while AI handles Dom, Lucas Reyes, and Mags Carter, the other three members of Bravo Squad.

What solo Campaign play means
The official Steam listing lists Single-player as a supported feature and says the Campaign can be played alone or with up to four players online. In Xbox Wire's Campaign preview, a solo player controls Marcus as AI takes the other three Bravo Squad roles.
That means the Campaign does not require you to bring other players. The solo preview describes the squad accompanying Marcus, rather than requiring additional human players to fill those roles. The Coalition also says enemy encounters are designed to challenge solo players in its Campaign gameplay updates.
How to decide which mode to play
Choose the Campaign
Play as Marcus
Invite others only if you want co-op
Solo play and co-op at a glance
| Campaign option | What the official sources say |
|---|---|
| Solo | Supported; AI controls the other three Bravo Squad members in the preview. |
| Online co-op | Up to four players. |
| Console split-screen | Two players. |
The player counts and split-screen detail come from the Xbox game page. The solo squad behavior comes from Xbox Wire.
Frequently asked question
Yes. The Campaign supports solo play. In the official preview, you control Marcus and AI handles Dom, Lucas Reyes, and Mags Carter.