|Full name||Mahatma Osumanu Otoo|
|Date of birth||February 6, 1992|
|Place of birth||Accra, Greater Accra, Ghana|
|Height||1.80 m (5 ft 11 in)|
|Sporting St. Mirren|
|2008–2009||Sporting St. Mirren||19||(8)|
|2009–2013||Hearts of Oak||117||(56)|
|2010||→ ES Tunis (loan)||14||(4)|
* Senior club appearances and goals counted for the domestic league only and correct as of 17:29, 4 February 2020 (UTC)|
‡ National team caps and goals correct as of October 15, 2013
Otoo began his career in the youth side for Sporting St. Mirren who signed him on his first professional contract when he was 16 years old on 30 October 2008. He earned the discovery player of the season title in the 2008/2009 season. Otoo signed for the 2009/2010 season with Accra Hearts of Oak SC finishing the season with a consecutive individual title winning the Ghana Premier League’s best player of the season. In 2010, Otoo moved to Tunisian club Esperance Sportive de Tunis on loan.
Mahatma Otoo returned to Hearts of Oak in the second round of the 2010/11 season, while a club finished 10th in the league. The following season, 2011/12, Otoo scored 10 goals in the league. Otoo was made captain of Hearts of Oak by Charles Akonnor because of his way of playing and fighting spirit. Otoo scored a hat-trick, which was the first in 2012/13 season in the 5-2 win over New Edubiase. Otoo scored a brace at Berekum Arsenals. Otoo renewed his contract with Accra Hearts of Oak for another season in May 2013. Otoo scored a hat-trick against Tema Youth on the final game of the season and became a top scorer of Ghana Premier League with 20 goals.
His performance attracted European clubs, with Club Brugge and Sogndal being front runners to land his signature. He moved to Sogndal on a three-year contract in the summer transfer window of 2013.
He left the club on 1 January 2017.
After his successful first season was called up for the Ghana national football team for the friendly game on 1 October 2009 against Argentina national football team and played in the game his internationally senior debut and played formerly in the Ghana national under-17 football team.