The 2017–18 Southampton F.C. season was the club's 19th season in the Premier League and their 41st in the top division of English football. In addition to the Premier League, the club also competed in the FA Cup and the EFL Cup. Southampton finished 17th in the Premier League table with seven wins, 15 draws and 16 losses. They were knocked out of the EFL Cup in the second round by Championship side Wolverhampton Wanderers, and were knocked out of the semi-finals of the FA Cup by Chelsea. The season was Southampton's first and only campaign with manager Mauricio Pellegrino, who replaced Claude Puel after one season in charge on 23 June 2017. Pellegrino was sacked with eight league games remaining on 12 March 2018, with the club in 17th position in the table, one point above the relegation zone. Mark Hughes, who played for the club between 1998 and 2000, was appointed as his replacement two days later.
Following the end of the 2016–17 season, Southampton released Martín Cáceres, Lloyd Isgrove, Cuco Martina and Harley Willard. They also sold Jason McCarthy to Barnsley for an undisclosed fee, Jay Rodriguez to West Bromwich Albion for £12 million, and Paulo Gazzaniga to Tottenham Hotspur for an undisclosed fee. Five players were sent out on season-long loans – Harrison Reed to Norwich City, Harry Lewis to Dundee United, Ryan Seager to Milton Keynes Dons, Sam Gallagher to Birmingham City, and Jordy Clasie to Club Brugge – while Olufela Olomola joined Yeovil Town on loan until January.
Southampton's first signing of the summer transfer window was Polish centre-back Jan Bednarek, who joined from Lech Poznań for £5 million on 1 July. The club's second signing followed on 8 August, when Gabonese defensive midfielder Mario Lemina joined from Italian club Juventus for an initial fee of £15.4 million, which could increase to a club record £18.1 million based on performance. On 14 August, Southampton signed free agent goalkeeper Jack Rose, who had most recently played for West Bromwich Albion. The following week, the club signed Dutch centre-back Wesley Hoedt from Italian side Lazio for £15 million.
When the transfer window reopened in January 2018, Dutch centre-back Virgil van Dijk joined Liverpool for £75 million, a world record fee for a defender. Young striker Marcus Barnes joined Yeovil Town on loan for the rest of the season on 5 January, while left-back Matt Target joined Championship side Fulham on loan for the rest of the season on 22 January. On 25 January, the club signed Argentine striker Guido Carrillo from French side AS Monaco for a club record fee of £19 million. Seager was recalled from his loan at Milton Keynes Dons on 26 January, and instead joined Yeovil Town until the end of the season.
Pre-season Southampton played their first pre-season friendly against Swiss club St. Gallen on 15 July 2017. The game ended in a goalless draw, with Saints coming close to scoring in the first half through Dušan Tadić and Nathan Tella, and in the second half through Steven Davis and Manolo Gabbiadini. A week later, the club drew 2–2 with Championship side Brentford, with both goals scored by striker Charlie Austin shortly after the half-time break. On 29 July the Saints beat French side Saint-Étienne 3–0, with two goals in two minutes scored by Manolo Gabbiadini and James Ward-Prowse, followed by a late header from Maya Yoshida. Southampton lost their first friendly of the season at St Mary's Stadium on 2 August, when they were beaten 4–0 by German side Augsburg. Three days later the club won their final pre-season friendly of the summer against Spanish side Sevilla, with goals coming from Jack Stephens in the first half and Manolo Gabbiadini in the second.
Premier League
August–October 2017
In their opening game of the season, Southampton were held to a goalless draw at home by Swansea City. The Saints enjoyed the majority of chances on goal, with Dušan Tadić, Manolo Gabbiadini and Maya Yoshida coming closest to scoring. The following week, Southampton beat West Ham United 3–2 to move up to fifth in the league table. Gabbiadini converted in the 11th minute with the club's first home goal since April, before Marko Arnautović was sent off for the visitors 12 minutes before half-time. Tadić doubled the hosts' lead with a penalty given away by former Saints defender José Fonte five minutes after the red card, before Javier Hernández brought one back for the Hammers on the stroke of half-time. Hernández equalised for West Ham in the second half, but a second penalty for the home side was scored by substitute Charlie Austin in the final minute of the game. The side's next match, away at Huddersfield Town, ended goalless. Nathan Redmond came close for the Saints in both halves, although the hosts enjoyed more chances on goal. Ryan Bertrand almost scored in injury time at the end of the game, but his header was cleared off the line by defender Tommy Smith.
After a two-week international break, Southampton suffered their first loss of the season when Watford beat them 2–0 at St Mary's. Abdoulaye Doucouré opened the scoring for the visitors shortly before half-time with a 25-yard volley, before substitute Daryl Janmaat doubled his side's lead in the 66th minute with a 30-yard shot. The Saints had only one shot on target the whole match, in injury time at the end of the game. The following week, Southampton beat Crystal Palace 1–0 at Selhurst Park. Steven Davis opened the scoring within six minutes, converting a Dušan Tadić cross from close range. The home side came close either side of half-time, with Fraser Forster saving shots from Christian Benteke and Jason Puncheon. On 23 September, Southampton hosted Manchester United and lost by a single goal. Romelu Lukaku opened the scoring after 20 minutes, following up after his header from a cross was saved. The hosts almost equalised several times later on, with Oriol Romeu coming closest on two occasions, one of which was headed off the line by Marouane Fellaini. Southampton lost again the following week at Stoke City. The hosts opened the scoring before half-time through a Mame Biram Diouf header, with Forster saving a Saido Berahino penalty a few minutes later. The Saints increased the pressure after the break, with Maya Yoshida scoring a volley in the 75th minute to equalise. Former Southampton striker Peter Crouch scored ten minutes later to secure the win.
Southampton drew 2–2 at home with Newcastle United on 15 October. Isaac Hayden opened the scoring in the 20th minute with a long-range shot following an earlier effort that was saved, and Joselu almost made it two before half-time when he hit the crossbar. Shortly after the break, Manolo Gabbiadini equalised for the hosts from close range, but within a minute and a half the visitors had regained the lead through Ayoze Pérez. The Saints were awarded a penalty later on for a foul on Shane Long, which Gabbiadini converted to secure a point for his side. The next week, the club beat West Bromwich Albion by a single late goal. The Saints enjoyed a number of chances to open the scoring, with Ryan Bertrand hitting the crossbar from a free kick and Shane Long missing from close range in the first half. Former Southampton striker Jay Rodriguez almost scored for the Baggies later on, but a solo effort from Sofiane Boufal in the 85th minute proved the only break of the game. Visiting Brighton & Hove Albion in their tenth game of the season, Southampton drew 1–1 and moved up to ninth in the table. Steven Davis opened the scoring after seven minutes with his second goal of the campaign, converting a rebound from James Ward-Prowse's free-kick. Glenn Murray equalised for the hosts after the break, with the deadlock held for the rest of the game.
November–December 2017 Southampton hosted Burnley on 4 November, losing 1–0 and dropping to 13th in the Premier League table. The hosts came close to scoring in the first half and early in the second through Sofiane Boufal, Nathan Redmond and Maya Yoshida, all of whom were denied by saves by goalkeeper Nick Pope. Sam Vokes scored the only goal of the match in the last ten minutes, heading in a cross. Two weeks later, the Saints lost again as Liverpool picked up a 3–0 win at Anfield. Mohamed Salah scored the first two goals for the hosts late in the first half, the first following a defensive error by the visitors and the second after a setup from Philippe Coutinho. The Brazilian midfielder scored the third goal himself in the second half. The club picked up their first win by more than a single goal of the season the following week, beating Everton 4–1 at home. The Saints dominated possession throughout the game, with Dušan Tadić opened the scoring in the 18th minute. Gylfi Sigurðsson equalised just before half-time, but a brace from Charlie Austin shortly after the break put the hosts back ahead. Steven Davis scored the fourth goal late on, as Southampton moved up to the top half of the league table. The team faced league leaders Manchester City in midweek, losing 2–1 late on. Maya Yoshida missed a close range volley in the visitors' best first-half chance, before Kevin De Bruyne opened the scoring for the hosts shortly after half time. Oriol Romeu equalised with his first goal of the season in the 75th minute, but Raheem Sterling won the game for City in the final minute of injury time at the end of the match.
On 3 December, Southampton travelled to nearby rivals Bournemouth, sharing the points in a 1–1 draw. Both teams had a number of chances on goal, but it was the hosts who opened the scoring through winger Ryan Fraser just before half-time, following a defensive error by Wesley Hoedt. Shortly after the hour mark, Charlie Austin scored his fourth goal of the season to bring the visitors level. Numerous chances for each side followed, but it ended level as the Saints moved back up to 11th in the table. The following week, the club hosted Arsenal in another 1–1 draw. Austin opened the scoring in the third minute, and came close to scoring more early on but for a number of offside decisions. The visitors dominated possession, but struggled to pressure Southampton's goal until two minutes from the end of the game, when Olivier Giroud headed in an equaliser for the Gunners. Southampton hosted Leicester City three days later in a midweek fixture, succumbing to a 4–1 loss to former manager Claude Puel's side. The Foxes opened the scoring after eleven minutes through Riyad Mahrez, with Shinji Okazaki doubling the lead just over 20 minutes later. Andy King added a third before half-time, Yoshida scored a consolation goal for the hosts just after the hour mark, and Leicester added a fourth through Okazaki's second.