EXHIBIT 23 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS 79 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS To SEI Investments Company: As independent public accountants, we hereby consent to the incorporation of our report, included in this Form 10-K, into the Company's previously filed Registration Statements File No. 2-73997, File No. 2-75629, File No. 2-78133, File No. 2-80841, File No. 2-89659, File No. 33-19952, File No. 33-24595, File No. 33-41602, File No. 333-41343, and File No. 333-63709. ARTHUR ANDERSEN LLP Philadelphia, Pa., March 27, 2001 80