Short answer: No. A Schengen visa does not grant entry to the United Kingdom. The UK is not part of the Schengen Area, which comprises 26 European countries that have abolished internal border controls.
Some travelers with a valid Schengen visa may transit airside through certain UK airports without a UK visa, but this depends on nationality, visa type, and airport. Always confirm with the UK Home Office or your airline before travel.
Any stay exceeding six months—whether for work, study, or family—requires a UK long-stay visa, irrespective of Schengen status.
Check the UK government's official visa-checker tool or contact the nearest British embassy/consulate for personalized guidance.