| Club: | Southend United |
| Season: | 2017–18 |
| Manager: | Phil Brown (until 17 January 2018) Chris Powell (from 23 January 2018) |
| Chairman: | Ron Martin |
| Stadium: | Roots Hall |
| League: | League One |
| League Result: | 10th |
| Cup1: | FA Cup |
| Cup1 Result: | First round |
| Cup2: | EFL Cup |
| Cup2 Result: | First round |
| Cup3: | EFL Trophy |
| Cup3 Result: | Second round |
| League Topscorer: | Simon Cox (10) |
| Pattern B1: | _CWD1718a |
| Leftarm1: | 282853 |
| Rightarm1: | 282853 |
| Shorts1: | 3069AB |
| Socks1: | FFFFFF |
| Pattern La2: | _southendunited1819t |
| Pattern B2: | _southendunited1819t |
| Pattern Ra2: | _southendunited1819t |
| Leftarm2: | FF9900 |
| Body2: | FF9900 |
| Rightarm2: | FF6600 |
| Shorts2: | FF6600 |
| Socks2: | FF6600 |
| Prevseason: | 2016–17 |
| Nextseason: | 2018–19 |
The 2017–18 season was Southend United's 112th year in existence and their third consecutive season in League One.[1] Along with competing in League One, the club also participated in the FA Cup, EFL Cup and EFL Trophy. The season covers the period from 1 July 2017 to 30 June 2018.
As of 2 June 2017, Southend United had announced five pre-season friendlies against Braintree Town, Bishop's Stortford, Ebbsfleet United, Brighton & Hove Albion[2] and Cambridge United.[3]
See main article: 2017–18 EFL League One.
See main article: 2017–18 FA Cup.
On 16 October 2017, Southend United were drawn away to Yeovil Town in the first round.[4]
See main article: 2017–18 EFL Cup.
On 16 June 2017, Southend United were drawn at home to Newport County in the first round.[5]
On 12 July 2017, Southend United were drawn in the Southern Group B against Colchester United, Gillingham and Reading U23s.[6] After finishing as runners-up in their group, Southend were drawn away to Peterborough United in the second round.[7]
|-|}
| Date from | Position | Nationality | Name | From | Fee | Ref. | |
|---|---|---|---|---|---|---|---|
| 1 July 2017 | Free | [8] | |||||
| 7 July 2017 | Free | [9] | |||||
| 11 July 2017 | Free | [10] | |||||
| 2 August 2017 |  | Free | [11] | ||||
| 3 August 2017 |  | Undisclosed | [12] | ||||
| 16 September 2017 | Free | [13] |
| Date from | Position | Nationality | Name | To | Fee | Ref. | |
|---|---|---|---|---|---|---|---|
| 1 July 2017 | Free | [14] | |||||
| 1 July 2017 | Released | ||||||
| 1 July 2017 | | Released | [15] | ||||
| 1 July 2017 | Released | ||||||
| 1 July 2017 | Released | ||||||
| 1 July 2017 | Free | [16] | |||||
| 1 July 2017 | Released | ||||||
| 1 July 2017 | Jordan Williams | Released |