| | DT | Signed (One-year contract (through 2018)) To |
| | DT | Signed/draft choice (Four-year contract (fifth-year option)) |
| | RB | Signed/draft choice (Four-year contract (through 2021)) |
| | S | Signed/draft choice (Four-year contract (through 2021)) |
| | DT | Signed/draft choice (Four-year contract (through 2021)) |
| | LB | Signed/draft choice (Four-year contract (through 2021)) |
| | CB | Signed/draft choice (Four-year contract (through 2021)) |
| | WR | Signed/draft choice (Four-year contract (through 2021)) |
| | G | Re-signed/unrest FA (Signed) |
| | G | Retired (Signed) |
| | G | Cut (Signed) |
| | S | Signed (Signed) To |
| | CB | Signed (Signed) |
| | WR | Signed (Signed) |
| | WR | Signed (Signed) |
| | CB | Signed (Signed) |
| | T | Signed (Signed) |
| | WR | Signed (Signed) |
| | TE | Signed (Signed) |
| | WR | Signed (Signed) |
| | DT | Signed (Signed) To |
| | LB | Signed (Signed) |
| | C | Signed (Signed) |
| | WR | Signed (Signed) |
| | RB | Signed (Signed) |
| | RB | Signed (Signed) |
| | S | Signed (Signed) |
| | S | Cut (Signed) |
| | LB | Cut (Signed) |
| | TE | Cut (Signed) |
| | DT | Cut (Signed) |
| | DT | Cut (Signed) |
| | DT | Cut (Signed) |
| | G | Re-signed/unrest FA (One-year contract (through 2018)) |
| | G | Team exercises option (Fifth-year option on rookie contract) |
| | T | Re-signed/rest FA (One-year tender (through 2018)) |
| | QB | Signed (Signed) To |
| | S | Cut (Signed) |
| | LB | Cut (Signed) |
| | QB | Cut (Signed) |
| | QB | Traded (w/ 2018 pick for 2018 6th-round pick) From |
| | NT | Re-signed/unrest FA (One-year contract (through 2018)) |
| | LB | Signed/unrest FA (One-year contract (through 2018)) To |
| | RB | Cut (Signed) |
| | S | Traded (w/ picks for three picks and 2020 pick) To |
| | WR | Signed/unrest FA (One-year contract (through 2018)) To |
| | LB | Signed/unrest FA (One-year contract (through 2018)) From |
| | WR | Signed/unrest FA (One-year contract (through 2018)) To |
| | CB | Signed (Two-year contract (through 2019)) From |
| | P | Signed (Signed) From |
| | WR | Re-signed/unrest FA (One-year contract (through 2018)) |
| | LB | Re-signed/unrest FA (Three-year contract (through 2020)) |
| | WR | Signed/unrest FA (Five-year contract (through 2022)) From |
| | QB | Re-signed (Four-year extension (through 2022)) |
| | TE | Signed/unrest FA (Two-year contract (through 2019)) To |
| | QB | Signed/unrest FA (Three-year contract (through 2020)) To |
| | C | Signed/unrest FA (Four-year contract (through 2021)) To |
| | WR | Declared Free Agent (Signed) |
| | WR | Declared Free Agent (Signed) |
| | TE | Declared Free Agent (Signed) |
| | QB | Traded (for CB Kendall Fuller and draft pick) From |
| | LB | Declared Free Agent (Signed) |
| | DE | Declared Free Agent (Signed) |
| | C | Declared Free Agent (Signed) |
| | WR | Declared Free Agent (Signed) |
| | CB | Declared Free Agent (Signed) |
| | NT | Declared Free Agent (Signed) |
| | DE | Signed/unrest FA (Three-year contract (through 2020)) To |
| | G | Declared Free Agent (Signed) |
| | G | Declared Free Agent (Signed) |
| | LB | Declared Free Agent (Signed) |
| | T | Restricted Free Agent (Signed) |
| | QB | Declared Free Agent (Signed) |
| | CB | Traded (w/ 3rd-round pick for QB Alex Smith) To |
| | DT | Declared Free Agent (Signed) |
| | LB | Declared Free Agent (Signed) |
| | LB | Declared Free Agent (Signed) |
| | WR | Signed/unrest FA (One-year contract (through 2018)) To |
| | S | Declared Free Agent (Signed) |
| | K | Re-signed (Three-year contract (through 2020)) |
| | RB | Cut (Signed) |
| | RB | Cut (Signed) |
| | T | Cut (Signed) |
| | S | Re-signed (Two-year contract (through 2019)) |
| | CB | Signed (One-year contract (through 2018)) To |