is an English professional football manager and former footballer. He is currently manager of EFL Championship club Portsmouth.

Mousinho began his professional football career at Brentford, having previously played for Chesham United and Notre Dame Fighting Irish, the latter whilst studying at the University of Notre Dame. He spent two and a half years at Brentford, before joining Wycombe Wanderers in June 2008 on a free transfer. Mousinho played regularly for Wycombe for two seasons, experiencing both a promotion and relegation during his time at the Buckinghamshire club. He signed for Stevenage in June 2010 on a two-year contract. In his first season at Stevenage, Mousinho helped the club earn the second of back-to-back promotions, scoring the winning goal in the 2010–11 League Two play-off final, as well as finishing as the club's joint top goalscorer for the season.

Following an injury-disrupted season during the 2011–12 season, Mousinho left Stevenage and joined Preston North End. In his final season at Preston, he was loaned out to Gillingham and then back to Stevenage before being released and joining Burton Albion in June 2014. He played 127 times for Burton over three seasons, winning the League Two title in his first season and promotion to the Championship a year later. In August 2017, he joined Oxford United, where he made 151 appearances before finishing his playing career in January 2023. Whilst playing, Mousinho was elected as chairman of the PFA in May 2021, a position he held until January 2023, leaving in order to take on his first managerial role, as head coach of League One club Portsmouth, where he led the team to promotion to the EFL Championship as champions of EFL League One in the 2023–24 season.