1. Eligible patients will have a new diagnosis of lung cancer and have sought a surgical consult relating to this diagnosis.
2. Surgery must be scheduled no sooner than 10 days after randomization and no more than twelve weeks after randomization.
3. Have smoked daily or nearly every day in the previous 6 months up to the date of surgical consult AND have smoked at least one puff in the previous 7 days.
4. Motivated to stop smoking, as indicated by a score of 6 or above on the Contemplation Ladder as defined in the protocol.
5. Within the 30 days before registration, no use of: 1) any pharmacologic treatment for smoking cessation, including buproprion or nicotine replacement therapy; 2) any nicotine delivery system (i.e., e-cigarettes and vape products); or 3) be enrolled in any formal behavioral treatment program for tobacco dependence as determined by patient report.
6. No allergies to and not currently using varenicline.
7. No suicidal thoughts as indicated by a positive (1+) response to question 9 on the PHQ9.
8. No active untreated clinically significant psychiatric condition (psychosis, bipolar disorder, or depression).
9. Negative pregnancy test (serum or urine) done ≤7 days prior to registration, for women of childbearing potential only. A female of childbearing potential is a sexually mature female who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).
10. No unstable angina, myocardial infarction, or coronary angioplasty within the past 3 months or an untreated cardiac dysrhythmia.
11. No history of seizures.
12. No unstable neurologic, hepatic, renal, cardiovascular, lymphatic, or metabolic disease.
13. Not currently on renal dialysis or has a history of significant renal impairment
14. No recent history (≤ 90 days) of substance abuse (outside of tobacco) defined by NIAAA as:

• If male, drinking >14 alcoholic beverages per week for past 1 month.
• If female, drinking >7 alcoholic beverages per week for past 1 month.
• Use of cocaine, heroin, club drugs (i.e., MDMA/"ecstasy"), methamphetamine, or hallucinogens (e.g., LSD) at any time during the past
• 1 month.
• Use of marijuana on a weekly basis for the past 1 month.

    15. Patients must be able to complete study questionnaires in English.

    16. ≥18 years of age

    17. No other household member or relative participating in the study.

    18. No known history of any condition or factor judged by the investigator to preclude participation in the study or which might hinder study adherence.

    19.Calculated creatinine clearance ≥ 30 mL/min

• Creatinine clearance (CrCl) will be calculated using the Cockroft-Gault equation as follows: CrCI (ml/min) = (140-age) x actual wt (in kg) / 72 x serum creatinine (mg/dL)