The build cost for Alligator Alcatraz appears to have been about $245 million to more than $250 million in signed Florida contracts, according to reporting from 2025.

What that means

  • AP reported Florida had already signed at least $245 million in contracts to set up and run the facility.
  • Another report later said Florida had signed more than $250 million in contracts for the project.

Why you may see bigger numbers

Some later coverage discussed much larger total costs because they included operating expenses, staffing, supplies, and closure-related costs, not just construction.

Practical takeaway

If you mean the initial build/setup cost , the best public estimate is roughly $245M–$250M+.

TL;DR: Building Alligator Alcatraz cost roughly a quarter of a billion dollars, with later estimates climbing much higher once operations are included.