His 16-year professional career was spent, other than in his country, in Portugal – five teams represented, mainly Porto with which he won five major titles, including one Primeira Liga championship and one UEFA Cup – and Cyprus (three clubs).
In December 1999, Clayton signed for fellow Primeira Liga club FC Porto, and went on to become an important attacking element.
[1] On 25 May of the following year, in the replay match of the final of the Taça de Portugal, he was directly involved in both of his team's goals in a 2–0 win over Sporting CP.
[2] On 17 October 2001, in the season's UEFA Champions League, Clayton scored a brace against Celtic in a 3–0 home triumph.
[6] After another Brazil spell with Sport Club do Recife, and another season at Penafiel (now in the Portuguese second level), Clayton moved to Cyprus.