The objective of this study was to investigate the bond characteristics between Ultra-High Modulus (UHM) carbon fiber reinforced polymer (CFRP) strengthened steel members and the flexural behavior of these members. A series of double lap shear joint tests with two different CFRP strip widths were carried out to evaluate the development length of the bond. Both UHM and Intermediate Modulus (IM) CFRP laminates were used to compare their performance. The bond test data is used to develop the novel UHM CFRP strip panels for steel beam strengthening. Debonding under flexural loads was also studied for UHM CFRP strengthened steel girders. Flexural tests were carried out under 4-point bending on several small scale wide flange beams. The first field application of UHM CFRP laminates in strengthening steel bridge girders in the United States was also carried out as part of the research. Full scale load tests carried out before and after the strengthening were utilized to measure the degree of strengthening achieved and checked against the expected results.