When Oliver Queen first arrived in Smallville, Lois and Clark had no romantic feelings for each other. When Lois and Olive first started to date, Lois was completely captivated by Oliver, but repulsed by the Green Arrow which often created awkward situations between the two. After Lois and Oliver broke up, twice, Clark was always there to lend a shoulder to cry on. Both Lois and Oliver would regret breaking up with each other, but many of those feelings for Lois quickly disappeated as Lois started to become closer with Clark. Eventually, it became a situation where Lois developed romantic feelings for Clark, although it took Clark longer to develop romantic feelings for her. However, when he did, they were just as strong. After Lois and Clark finally became a couple, Oliver was left feeling depressed as his love for Lois still lingered, even though she told him she was interested in Clark.
Oliver Queen arrived in Smallville when he was revealed to be the thief who stole Martha Kent's necklace as a green thied. Lois was constantly obsessed with figuring out the thief's identity. While trying to figure out his identity, she was kidnapped by his enemies and tortured. Even after Lois was rrescued by the thief himself, she still attempted to unmask his identity. Luckily, Clark was able to intervene. Not long after Lois met Oliver Queen, boy billionaire, and the two began to date.
Clark warned Oliver, however, that if he did not tell Lois the truth about his identity, their relationship would be ruined.
Clark's warning proved to be true. When Lois discovered that Oliver was Green Arrow. She became tired of Oliver constantly disappearing with no explanation. They broke up in Justice and Oliver left town with the Justice League.