Career intelligence is of major importance for students to understand their aptitudes, interests, and abilities. The aims of this quantitative research are 1) to develop an Online Career Intelligence Test (OCIT) for Thai high school students, and 2) to confirm factor analysis of the test. Multistage random sampling was performed on a sample of 2,000 high school students from 6 regions of Thailand. The instrument was an online individual test (OCIT) to identify students' career abilities, based on several different Theories integrated into a concept with a Thai context namely Gardner's Multiple Intelligence Theory and Holland's Theory, and Career Interest. The data was analysed using confirmatory factor analysis (CFA), means (M), and standard deviation (S.D.). The results were: 1) This test was composed of 9 factors; verbal-linguistic Intelligence, logical and mathematical intelligence, spatial and visual intelligence, bodily or kinesthetic intelligence, musical intelligence, interpersonal intelligence, intrapersonal intelligence, natural intelligence, and existential intelligence, totaling 90-items. 2) The findings of CFA showed that nine components of the OCIT corresponded significantly with empirical data by CFA (x[superscript 2]= 48.89, df=17, x[superscript 2]/df=2.87, RMSEA=0.031, RMR=0.00, GFI=0.99, AGFI=0.99). The OCIT can be used to assess students both effectively and conveniently.