Kelle Willem Roos (born 31 May 1992) is a Dutch professional footballer who plays as a goalkeeper for Serie C Group A club Triestina.

[11] Having received offers from the Netherlands and England, Roos went on to join Conference Premier side Nuneaton Town on 8 November 2013,[12] signing a contract until the end of the 2013–14 season.

[14] There were initial rumours and controversy over his debut, with led chief executive Ian Neale to deny that any pressure was placed on manager Kevin Wilkin to play Roos.

[15] His debut came on 23 November, in a 1–0 victory over Chester at Liberty Way, where he earned praise for a "fine" late save from a close-range Jason Jarrett strike.

[18] His form drew the attention of Premier League club Liverpool, with whom he spent a week's trial in early January 2014, as well as Everton, Sunderland and Cardiff City.

[7][13] He also spent time training with Ipswich Town and Bolton Wanderers and was scouted by Crystal Palace, Queens Park Rangers and Bournemouth.

He signed a 2+1⁄2-year contract for an undisclosed fee, believed to be around £30,000 plus add-ons, including the requirement that Derby play a pre-season friendly with Nuneaton in the summer.

[23] On 15 July 2015, Roos joined Championship rivals Rotherham United on a season-long loan deal, along with team-mate Farrend Rawson.

[24] However, he got off to a poor start with a 4–1 defeat to Milton Keynes Dons at the New York Stadium on 8 August, which led to heavy criticism from "Millers" fans on social media.

[25] Roos returned to Derby just six weeks into the loan period after conceding ten goals in his four appearances, leaving Rotherham bottom of the table.

[36] He made his debut for the "Valiants" later that same day in a 1–1 draw with Forest Green Rovers at Vale Park, which proved to be Brown's last game as manager.

[37] Seven days later he spilled a routine cross to allow Yeovil Town the equalising goal in a 1–1 draw, but was backed by caretaker manager David Kelly, who said "he is a good presence for us and he will get over it".

[39] On 8 December 2017, he then joined League One side Plymouth Argyle on an emergency loan after injuries to Luke McCormick, Kyle Letheren and Robbert te Loeke.

[42][43] With regular custodian Scott Carson out injured, Roos finally made his league debut for Derby on 19 January 2019, helping the "Rams" to 2–1 victory over Reading.

[48] Following some poor appearances, manager Phillip Cocu dropped Roos for Huddersfield Town loanee Ben Hamer after he conceded three goals at Fulham on 26 November 2019.

[61] The team enjoyed a positive start to the 2022–23 campaign, sitting in third-place as the 2022 FIFA World Cup enforced winter break began.

[62] On 15 January, Roos tore his hamstring in the Scottish League Cup semi-final defeat to Rangers at Hampden Park and was sidelined for four months; fellow Dutchman Jay Gorter was signed on loan to replace him.