União Desportiva Oliveirense (UDO), commonly known as Oliveirense, is a Portuguese sports club from the city of Oliveira de Azeméis, in Aveiro District. The club was founded on 25 October 1922. The main football team currently plays at the Estádio Carlos Osório which holds a seating capacity of 4,000 and plays in Liga Portugal 2. As a multisports club it fields very successful teams in rink hockey and basketball as well. Its rink hockey team has won the Taça de Portugal on three occasions whilst its basketball team has won the Portuguese Basketball SuperCup and the Portuguese Basketball Cup. The Kelly–Simoldes–UDO cycling team, which holds a UCI Continental team licence, is affiliated with União Desportiva Oliveirense.

Oliveira de Azeméis is a city and a municipality located in Porto Metropolitan Area in Portugal. Administratively, the municipality belongs to the District of Aveiro. The population of the municipality in 2011 was 68,611, in an area of 161.10 km2. The city itself has a population of about 20,000. Oliveira de Azeméis is located 35 km to the south of Porto. It is less than 20 km far from the Atlantic Ocean. The municipal holiday is the Monday that follows the 2nd Sunday of August.