[4] He spent the next two seasons learning from former Manchester United, Luton Town, Aston Villa and Coventry City goalkeeper Les Sealey and sitting in the pecking order behind Craig Forrest, Bernard Lama and Shaka Hislop.

[5] Eventually, after the club was relegated in 2002–03 and David James moved to Manchester City in January 2004,[10] Bywater became a regular starter in the first-team, making 23 appearances as West Ham reached the First Division play-off final, where they were beaten 1–0 by Crystal Palace.

"[12] He soon had to share the role of the club's primary keeper with Jimmy Walker who was brought in from Walsall in June 2004 to provide competition for Bywater.

[14] The signing of Roy Carroll in June 2005[15] and the re-signing of Shaka Hislop on a one-year contract in July 2005[16] once again limited Bywater's first-team opportunities and he joined Coventry City in August 2005, on loan until the end of the year,[17] where he made 14 appearances.

[21] In June 2007, Bywater reiterated his desire to play for England and his hopes to be noticed in the 2007–08 season, saying "I grew up with a few of the lads like Paul Robinson, Rob Green and Chris Kirkland and they are good but I don't think they are anything special.

[27] In December 2009, after keeping two successive clean sheets, manager Nigel Clough praised Bywater's performances in the two games: "Stephen has been exemplary.

"[28] An injury sustained away to Reading in March 2010 saw Bywater ruled out for two games which brought to an end a run of 71 consecutive league appearances in the Derby goal.

After Derby secured survival with a 1–1 draw with Crystal Palace, Bywater sat out the last two games of the season to rest a sprained rib joint.

Bywater played every minute of Derby's opening 11 games of the season, keeping two clean sheets, before a wrist injury sustained in training during the October international break ruled him out for a month.

[35] On 20 September 2011, Bywater joined Sheffield Wednesday on loan for 3 months due to an injury picked up by first choice 'keeper Nicky Weaver.

[36] Bywater's loan spell proved to be very successful, with Wednesday losing just 1 of his 12 games and keeping six clean sheets, moving boss Gary Megson to state his intention to make Bywater's move permanent,[37] with Derby manager Nigel Clough confirming talks with Wednesday over a potential transfer.

[39] On 31 December 2011, Bywater signed for Wednesday on a permanent transfer, with a contract until the end of the 2011–2012 season, the move went ahead on 1 January 2012.

[41][42] Wednesday secured promotion to the Championship by coming runners up in League One, narrowly finishing ahead of local rivals Sheffield United.

[55] In summer 2017, the Brewers decided to release McLaughlin and Bywater was installed as first choice,[56] playing 44 league games in 2017–18, however Burton were relegated from the Championship at the end of the season.

Following the signing of Ben Garratt in October 2019, Bywater dropped to third choice, and stopped taking a salary and attending training while remaining available in an emergency.

Bywater has reiterated on several occasions his intention to move into mixed martial arts and cage fighting when his playing career ends, saying "I have told my agent that one day I am going to take it up!

In an October 2007 interview with Clare Tomlinson on Sky Sports' Goals on Sunday programme he spelt out the word "cunt" whilst live on air as part of an anecdote.

The installation – a horse box with mattresses and a sex doll strapped to it with graffiti sprayed on the side – brought complaints from neighbours, who described the piece as "very ugly" and an "eyesore".

[63] Bywater, who claimed that art was his latest hobby and the installation was his "masterpiece", issued a statement via Derby County stating "I would like to apologise to any supporters and local residents in Derbyshire who have been offended.

"[64] He eventually auctioned the piece, announcing the eBay sale via his Twitter page, saying all the proceeds would be donated to the Teen Pride charity.