After the Australian Open, Vinci went to compete at the St. Petersburg Ladies' Trophy, where she was the sixth seed and the defending champion. She started off the tournament by beating Tímea Babos in the first round, 6–3, 3–6, 6–4 before she defeated qualifier Andrea Petkovic, 6–4, 6–4. In the quarterfinals, Vinci was defeated by eventual champion Kristina Mladenovic, 6–1, 6–4. Due to losing in the quarterfinals, Vinci failed to defend her title. At the Qatar Total Open, Vinci lost in the first round to qualifier Lauren Davis, 2–6, 3–6. Seeded 16th at the Dubai Tennis Championships, Vinci was upset in the first round by world No. 55, Kristýna Plíšková, 3–6, 7–5, 6–3. Vinci had a 6–3, 5–4 lead and was serving for the match before Plíšková made a comeback to win the match. Seeded 26th at the BNP Paribas Open, Vinci received a first round bye. She lost in the third round to eighth seed Svetlana Kuznetsova, 2–6, 6–2, 1–6. Seeded 25th at the Miami Open, Vinci was stunned in the second round by qualifier Taylor Townsend, 6–3, 6–2. After Miami, Vinci played at the first edition of the Ladies Open Biel Bienne. As the fourth seed, she was upset in the first round by world No. 58, Kristýna Plíšková, 6–4, 6–4.