The Saints, who won promotion via the play-offs with Martin last season to return to the top flight at the first time of asking, have picked up just five points from their first 16 league games in 2024/25.
It leaves them nine points from safety before Christmas, with many believing that the campaign is now a write-off and that Southampton should begin planning for another season in the Championship.
The club had tried to persevere with Martin, who stuck to his principles of trying to play out from the back and dominate possession like they did in the second tier. However, last night's thrashing at the hands of Spurs ended up being the final straw.
The Saints were 4-0 down going into first-half stoppage time, with Martin walking back into the dressing room early for his team talk and missing the fifth goal as a result. Supporters got behing the team in the second half, but they struggled to threaten, with boos meeting the full-time whistle as well as a banner that read: 'R.M. Get out of our club!!'.
This sign spotted by our photographer. #SaintsFC pic.twitter.com/kGBnQ4Gx0Q
— Alfie House (@AlfieHouseEcho) December 15, 2024
In a statement late last night, the board wrote: "Going into the start of the season, we all knew the challenges that we would face this year as we readjusted to life in the top flight, competing in the best and most competitive league in the world.
"However, the reality of our situation is clear. The board have supported Russell and his staff and been open and transparent regarding our expectations. We have all been on the same page in recognising the urgency of needing results to improve.
"We would like to take this opportunity to thank Russell and his staff for all the hard work and dedication they have given the club on and off the pitch over the last 18 months. Everyone connected with Southampton FC will always have fantastic memories of last season, especially the play-off final win in May.
"Current Under-21s Manager Simon Rusk will take charge of the team on an interim basis until we announce a permanent replacement."
Sheffield Wednesday manager Danny Rohl is the current 1/1 favourite via to Sky Bet. The 35-year-old only started his senior management career last year, having guided his side to safety in the Championship. Kieran McKenna has faced him once so far, winning 6-0 against his Owls team at Portman Road back in March.
Danny Rohl is the current favourite to take over at St. Mary'sDanny Rohl is the current favourite to take over at St. Mary's (Image: PA)
West Brom boss Carlos Corberan and ex-Chelsea boss Graham Poter (both 7/1) are also in the mix alongside former West Ham manager David Moyes (10/1).
There was another sacking in the Premier League over the weekend as Wolves parted company with Gary O'Neil following their 2-1 defeat at home to Ipswich, which leaves them 19th in the Premier League. Reports suggest that Portuguese head coach Vitor Pereira - currently in charge of Saudi side Al Shabab - will be his replacement.
Elsewhere, Town's upcoming FA Cup opponents Bristol Rovers have sacked manager Matt Taylor, with the Gas sitting 20th in League One, two points above the relegation zone.