|Full name||Carlos Alberto de Oliveira Secretário|
|Date of birth||12 May 1970|
|Place of birth||São João da Madeira, Portugal|
|Height||1.75 m (5 ft 9 in)|
|Playing position||Right back|
|* Senior club appearances and goals counted for the domestic league only.
During his 17-year career, in which he appeared in 341 Primeira Liga games and scored 12 goals, he played for six clubs in his country including Porto, with which he won 18 major titles. He also briefly represented Real Madrid.
After making his professional debuts with Gil Vicente F.C. in the second division, Secretário, who was born in São João da Madeira and started his career as a midfielder, moved to the Primeira Liga with F.C. Penafiel in 1989, then spent one additional season with fellow league team F.C. Famalicão. In 1992–93 he signed with S.C. Braga, where he spent another campaign.
In the 1993 summer, Secretário joined league club FC Porto, quickly establishing himself as an undisputed starter, in defense or midfield – after João Domingos Pinto's retirement, he played almost exclusively as a right back – and helping the northerners to two leagues, one Cup and one Supercup in his first spell. He attracted attention from Real Madrid, which signed the player in July 1996, but he would encounter extreme difficulties in carving a starting niche with the Spanish club, which was aggravated with the January 1997 signing of Italian Christian Panucci; in a bizarre incident in a game against Real Betis at the Santiago Bernabéu Stadium, a delay was caused by a rabbit presumably thrown into the fray from the terraces, and he was quick enough to catch it. "Secretário may or may be not a good player," said TV commentator Arsenio Iglesias at the time, "but he is indeed a great hunter."
Secretário returned to Porto in January 1998 for six-and-a-half additional seasons, and would go on to conquer the UEFA Cup and the UEFA Champions League in back-to-back years, although he was now only backup to emergent Paulo Ferreira. On 14 March 2002 he was sent off during a 2–1 continental home win over Panathinaikos FC, receiving a three-match suspension.
In June 2005, Secretário retired after one year with F.C. Maia (second level). Two years later he started his coaching career with the same side, but it was now in the fourth. He continued working in the lower leagues in the following seasons.
|1||3 June 1995||Estádio das Antas, Porto, Portugal||Latvia||2–0||3–2||Euro 1996 qualifying|
- Primeira Liga: 1994–95, 1995–96, 1997–98, 1998–99, 2002–03, 2003–04
- Taça de Portugal: 1993–94, 1997–98, 1999–2000, 2000–01, 2002–03
- Supertaça Cândido de Oliveira: 1994, 1998, 1999, 2001, 2003
- UEFA Champions League: 2003–04
- UEFA Cup: 2002–03
- Real Madrid
- Secretario medita negociar su traspaso (Secretário thinks about a buy-out); El Mundo, 11 January 1997 (in Spanish)
- They think it's all over … it is meow, as cat invades Anfield pitch; The Guardian, 7 February 2012
- Secretário gets three-match ban; UEFA.com, 14 March 2002