Philip B. Brown, 55, a Washington lawyer active in civic affairs here, died Monday after suffering a stroke on Harbour Island in the Bahamas, where he was vacationing at his winter home.

A senior partner of Squire Sanders and Dempsey, he was in charge of the law firm's Washington office.

Mr. Brown had joined the law firm of Cox, Langford and Brown here in 1946 and was a senior partner there when it merged 10 years ago with Squire Sanders and Dempsey.

He was secretary and a director of the Stanwick Corporation, management consultants in Arlington, and secretary of the Italian Economic Corporation in Washington.

He was born in Middletown, Conn., where he graduated from Wesleyan University and was a member of Phi Beta Kappa. He earned a degree at Yale University Law School in 1946, and was on the board of editors of the Yale Law Journal.

Mr. Brown had been active with the Washington Home Rule Committee, serving in the 1950s as treasurer and legislative committee chairman.

He was counsel for the Georgetown Children's House and trustee and counsel for the Lake Placid Education Foundation in New York. He was past president of the board of directors of the Madeira School in Virginia and of the Yale Law School Association here.

He served on the board of the Belgian-American Chamber of Commerce. For his work as a representative of the Belgian government in legal matters over the years, he was made an officer of that country's Order of the Crown and a commander of the Order of Leopold II.

Mr. Brown belonged to the Metropolitan Club.

He is survived by his wife, the former Elinor Kenney, and three daughters, Elizabeth, Sarah and Marcia, all of Washington, and two sisters, Elizabeth Cubeta of Middlebury, Vt., and Jeanne Krochalis of Lexington, Mass.