Vivo seems to be gearing up to launch its X300 series pretty soon. The smartphones have been part of the rumour mill for quite some time now. A new report has now indicated an October 2025 launch window for the new "X" series devices.
Tipster Smart Pikachu believes that Vivo will make the X300 and the X300 Pro smartphones official in China in just two months' time. While the leaker has not explicitly mentioned the launch date in the Weibo post, we believe it is going to happen sometime after October 8, 2025.
This is because China is gearing up to experience its long holidays in October in the form of the Mid-Autumn Festival (October 6) and the National Day (October 1 to October 8). Hence, it is unlikely that Vivo will launch any device before these events.

Apart from this, rumours also hint at the existence of the Vivo X300 Ultra and the Vivo X300 Pro Mini. However, these smartphones will probably not launch before 2026. Early speculation hints at a Q1 2026 launch window for these smartphones.
As for the X300 and X300 Pro rumoured specifications, the standard X300 is expected to arrive with a compact form factor with a 6.3-inch display. This is in contrast to the 6.67-inch screen that we saw on the Vivo X200. It is expected to feature a 1.5K 120 Hz 10-bit flat OLED panel.

Speaking of the X300 Pro, it is expected to carry forward the 6.78-inch screen size of the Vivo X200 Pro. We believe it is going to be a QHD+ 120 Hz quad curved AMOLED panel same as that of the 2024 flagship.
Talking about performance, both smartphones will likely draw their power from the upcoming MediaTek Dimensity 9500 processor.
And just like the Vivo X200 series, the X300 lineup will also get backed by Zeiss optics. The triple rear camera setup is expected house a 200 MP primary 1/1.4 sensor, a 50 MP ultra-wide lens and a 50 MP telephoto IMX882 3X unit.

Lastly, previous leaks have revealed over 7,000mAh of battery capacity for both smartphones. That said, we will know for sure once the smartphones officially break cover. At the time of writing, these are all speculations. So, take them with a grain of salt. We will be sure to report on any official information as and when it emerges.