O'Meara started his college education at the University of Minnesota before taking a leave of absence to serve in the US Army in World War I.
Upon his return, he completed his studies in journalism at the University of Wisconsin–Madison, graduating Phi Beta Kappa in 1920.
Following his time with the newspaper, he moved to Chicago to work for the advertising agency J. Walter Thompson.
O'Meara was married in 1922 to Esther Arnold, with whom he had four children: Donn, Ellen, Deirdre, and Wolfe.
They lived in several places including Washington Mews, NYC; Woodstock, NY; Bisbee, AZ; and Danbury, CT.