Background The internet has become an important channel for the public to obtain information on e-cigarettes, and online attention toward e-cigarettes may reflect, to some extent, the level of public cognition and interest, carrying significant public health implications. Objective To analyze the online attention toward e-cigarettes among the Chinese public and reveal its spatiotemporal trends, providing a scientific basis for the formulation of e-cigarette regulatory policies. Methods Based on data from the Baidu Index platform, the daily average search index data for netizens across various provinces in China from 2018 to 2024 were obtained as a quantitative measure of e-cigarette online attention by using “e-cigarette + electronic cigarette” as search terms. The seasonal concentration index was applied to examine the degree of monthly concentration of attention, and global spatial autocorrelation (Global Moran’s I) was used to characterize the overall spatial clustering pattern of e-cigarette online attention at the provincial scale. Results From 2018 to 2024, the overall online attention toward e-cigarettes in China was 3650, 4271, 5112, 7109, 4345, 2603, and 1527 times·d⁻¹, respectively, with the seasonal concentration index narrowing over time (from 0.885 in 2018 to 0.817 in 2024). Peak months for online attention were concentrated in March and November, while levels were lower in August and December. The provinces with higher per capita e-cigarette online attention were mainly located in the eastern and western regions. In general, the global Moran's I values for e-cigarette online attention in China from 2018 to 2024 were 0.194, 0.154, 0.184, 0.173, 0.166, 0.159, and 0.146, respectively, indicating positive spatial autocorrelation. Conclusion Significant spatiotemporal disparities are observed in the e-cigarette online attention in China. Temporally, overall network attention exhibits an “increase-then-decrease” trend. Spatially, the per capita attention demonstrates a distinct pattern characterized by higher levels in the eastern and western regions and lower levels in the central regions. These findings underscore the need for targeted e-cigarette regulatory policies tailored to specific time periods and geographic regions.