Born in Kirkcaldy, she grew up in the town of Buckhaven, Fife. Mitchell went on to become the only girl to play for her local high school team at the age of twelve. She started her career with St Johnstone Girls, alongside fellow future Frauen-Bundesliga player Lisa Evans, before both girls joined Scottish Women's Premier League champions Glasgow City in August 2008. At the end of the 2012 season, Mitchell had a trial period in Denmark with earlier Champions League opponents Fortuna Hjørring, before heading for further trials in Sweden and Germany. Mitchell signed professionally for Frauen-Bundesliga side SGS Essen in January 2013. After just four months, reports in Germany linked Mitchell with a transfer to English champions Arsenal. Arsenal confirmed the move on 22 July 2013. Whilst at Arsenal, Mitchell won an FA Cup in 2014 with WSL Cups coming in 2013 and 2015. With the Gunners, she also went on a successful run to the FA Cup final of 2016. Arsenal beat Chelsea 1–0 at Wembley and Mitchell lifted the 2016 FA Cup. On 3 January 2020, it was announced that Mitchell would be joining Tottenham Hotspur on loan for the rest of the season.
International career
After captaining both the national Under-17 and Under-19 teams, Mitchell made her debut with the senior Scottish national team against France in May 2011. Despite conceding a penalty in Scotland's 1–1 draw, Mitchell's contribution was praised by coach Anna Signeul: "Emma Mitchell did really well on her first appearance. It is a shame that she conceded the penalty, it was just a bit of inexperience to be honest, but she didn't let her head go down and kept working hard." Mitchell attended the Scottish Football Association National Performance Centre at the University of Stirling. Mitchell scored her first goal for the Senior women's side against Iceland in August 2012 and later that year scored against Spain in Scotland's 2013 UEFA Women's Euro Play-off defeat. Mitchell was ruled out of Scotland's squad for UEFA Women's Euro 2017 by a hamstring injury. After injury disrupted her appearances for Arsenal in the 2018–19 season, she was left out of the 23-player Scotland squad for the 2019 FIFA Women's World Cup in France.
Personal life
In October 2019, Mitchell spoke about her struggles with her mental health issues.
Honours
Club
Glasgow City
Scottish Women's Premier League: 2009, 2010, 2011, 2012