Cast (in credits order) complete, awaiting verification
| Phyllida Lloyd | ... | Self - Director | |
| Meryl Streep | ... | Self / Margaret Thatcher | |
| Jim Broadbent | ... | Self / Denis Thatcher | |
| Rest of cast listed alphabetically: | |||
| Harry Lloyd | ... | Young Denis Thatcher (archive footage) (uncredited) | |
| Alexandra Roach | ... | Young Margaret Thatcher (archive footage) (uncredited) | |
