Giacomelli played in Brazil for Ponte Preta and Indipendente, in Hong Kong for Sai Kung Friends and Happy Valley, in Lebanon for Sagesse and Nejmeh, and in Greece for Apollon Kalamarias.
After playing for Ponte Preta in his native country, Giacomelli joined Hong Kong team Sai Kung Friends in 1998.
After one season, he joined Happy Valley before moving to Lebanon in 2000, where he signed for Sagesse.
[1] At Sagesse, Tommy scored 41 league goals during his four year stay.
In 2006, Giacomelli returned to Sagesse where he scored 14 goals during the season, before moving once again to Happy Valley in 2007.