Senica's history is closely related with the Branč castle, built in 1251–1261. It was first mentioned in 1256 and received its city privileges in 1396, confirmed in 1463 and 1492. The city was affected by Turkish wars, anti-Habsburg uprisings and reformation and counter-reformations in the 17th century. In 1746, it became seat of the district within the Nitra county.
A significant silk-making company is based in Senica. The company was established in 1954. The name was ″Slovenský hodváb" and from 2005 is stoped the viscoserayon production and after mergering the company with company Kord to Slovkor, it continues only with production of Synthetic fiber for technical purposes. In February 2014 was demolished the factory chimney, which dominated the city more than half century and was visible from long distance. The demolition is on YouTube
OMS lighting, one of the biggest luminaire companies in East-Central Europe, is also based in Senica. With around 1000 employees and exporting 98% of its production to more than 100 countries, the company is a referent in the city economy.