IF Brommapojkarna Nordfeldt began his career in
IF Brommapojkarna, famous for its academy. He was promoted to the first team for the season of 2006, when the team was playing in
Superettan. Nordfeldt did not play any league matches that year or the following year when the team was playing for the first time in
Allsvenskan. In 2008,
IF Brommapojkarna were back in Superettan and both goalkeepers,
Mattias Asper and
Kristoffer Björklund, had left the club. Nordfeldt started his first year as a senior and when the season ended, the club had seen a promotion back to the Allsvenskan. He had started 29 out of 30 league matches, conceding 27 goals, and achieving 12 clean sheets. Nordfeldt signed a new contract in the beginning of 2009, keeping him at the club until 2012. As newcomers for the season of 2009, the club was seen as favourites for relegation, but finished a comfortable 12th. He made 21 league appearances, conceding 31 goals and keeping six clean sheets. On 2 August 2010, there were several scouts spotted at Grimsta to watch the match between
IF Brommapojkarna and the league leaders
Helsingborgs IF. The clubs thought to be interested in Nordfeldt were
Ajax,
Borussia Mönchengladbach,
Hannover 96,
Heerenveen, and
Sampdoria.
Heerenveen On 6 March 2012, Nordfeldt signed a three-and-a-half-year deal at Dutch top flight club
SC Heerenveen. He featured over 100 times for the Dutch side, helping them reach the Eredivisie play-offs for Europa League qualification in each of his three seasons at the club.
Swansea City On 23 June 2015, Nordfeldt signed for
Premier League side
Swansea City on a three-year deal for an undisclosed fee. He was signed to compete with
Łukasz Fabiański for the starting position, following the departures of goalkeepers
Gerhard Tremmel and
David Cornell earlier in that transfer window. Nordfeldt made his Swansea City debut on Tuesday 25 August in their
League Cup match against
York City where he played the full 90 minutes in a 3–0 win which resulted in his first clean sheet for the club. Nordfeldt made his Premier League debut in the last match of the
season against
Manchester City.
AIK On 9 August 2021, Nordfeldt signed a short-term contract with the Allsvenskan club
AIK. The deal ran until 31 December 2021. He made his debut for the club on 19 August 2021 in the second round of the 2021/2022
Swedish cup against
Rågsveds IF. The match ended in a 5–0 victory for AIK, with two goals scored by
Erik Ring, and Nordfeldt kept a clean sheet in his first appearance for the club. He made his Allsvenskan debut just three days later, when AIK defeated
BK Häcken 2–1 at
Friends Arena. His first clean sheet in the league came in the following match, a 2–0 win over
Örebro SK on 28 August 2021. At the end of December 2021, as his contract with the club was about to expire, Nordfeldt signed a four-year deal with AIK, keeping him at the club until 31 December 2025. In August 2025, he signed a new agreement extending his contract until 31 December 2027. ==International career==