Williams & Connolly LLP has a long history of involvement in trust and estate litigation. In recent years, the firm has been retained to handle several significant will contest cases in the Washington metropolitan area. The firm represented Marlena Cooke in her dispute with the Estate of Jack Kent Cooke, former owner of the Washington Redskins; Williams & Connolly lawyers successfully defended Betty Brown Casey in the will contest trial over the estate of her husband, Eugene B. Casey; and represented one of the trustees in the Cafritz Estate litigation.

The firm has also represented long-standing banking clients and others in breach of fiduciary duty cases challenging the management of trust assets, disputes among trustees and between trustees and beneficiaries, investment clients seeking redress for mismanagement and misappropriation of their funds, and disputes concerning the management and operation of charitable foundations.

Firm lawyers have also handled probate litigation, including disputes over the appointment and removal of executors and trustees, elective share claims, and marital agreements. Moreover, the firm's tax and trust and estate lawyers have offered advice on all aspects of probate, estate tax returns, and trust and estate administration and management.