The North West law firm is opening a fourth Merseyside office, taking 6,500 sq ft at Brunswick Business Park in Liverpool's south docks.
The company already has offices in Liverpool city centre, Prenton and Moreton and has signed a ten-year lease on space in South Harrington Building with landlord Doobra Investments VI at an undisclosed sum.
Simon Gibson, managing partner of Kirwans, said: "We already have offices in three fantastic locations in Wirral and Liverpool's commercial district but the requirement was there for a fourth office in order to keep pace with our expansion plans and the expectations of our clients.
"We have grown from around 80 staff at the start of 2010 to more than 100 and we continue to look to bring on board the best legal talent at all levels. We have also significantly strengthened our management team not just across our many legal disciplines but also in IT, HR and marketing."