Taylor, 30, will move to the Recreation Ground from the European Cup quarter-finalists Stade Francais.
The back-row forward has won 68 caps, making his Test debut against the USA in 2000, and he also toured with the 2001 and 2005 British and Irish Lions to Australia and New Zealand.
His 2001 Lions trip though was ended by a knee injury, while he did not play at all four years later after a hamstring problem forced him to fly home early.